PRESENTATION ON TOUCH
TECHNOLOGY
Presented by:- TANU AGRAWAL
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. However, if the object
sensed is active, as with a light pen.
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
Dr. Samuel Hurst
The father of the touch screen technology
is Dr. Samuel Hurst. In 1971, while he was
working as an instructor at the University of
Kentucky Research Foundation, he had to
read a great volume of information during
the graduation exams. In an effort to save
some time he invented the first touch sensor
that he called “Еlo graph”(electronic
graphics), which allowed him to enter data
faster.
First Touch Phone
Apple was the first with a touch
screen phone in 1983. Jason
Ford of Elo Touch Systems, the
company
whose
founder
invented
touch
screen
technology, for providing the
touch technology. In 1971, the
first "touch sensor" was
developed by Doctor Sam
Hurst.
First Touch Mobile
The Nokia 7710 is a first touch
screen mobile phone model
produced by Nokia. The 7710 is
based on the Nokia 7700 which
was never released. It is Nokia's
first, and so far only smart phone
to run the Series 90 GUI a top
the Symbian OS.
Types of Touch Technologies
There are mainly 4 types of touch Technologies:1.Resistive
2. Surface acoustic wave
3. Capacitive
4. Infrared
Resistive
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. 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. It is used
in Grocery Stores, Hotels, Restaurants and
Retail Stores.
Advantages & Disadvantages of Resistive
• Advantages
– Cost-effective solution
– Activated by any stylus
– Very accurate
– Low power requirements
– Liquids won't affect touch screen performance
• Disadvantages
– Polyester surface can be damaged
– Lower endurance (35 million touches)
Surface Acoustic Wave (SAW)
Surface
acoustic
wave
(SAW)
technology
uses ultrasonic waves that pass over the touch screen panel.
When the panel is touched, a portion of the wave is
absorbed. This change in the ultrasonic waves registers the
position of the touch event and sends this information to
the controller for processing. SAW touch screen technology
is suggested for use in ATMs, Amusement Parks, Gaming
Environments, Industrial Control Rooms etc.
Advantages & Disadvantages of SAW
• Advantages
– Durable glass construction
– High optical clarity
– Activated by a finger, gloved hand, or soft tip stylus
• Disadvantages
– Moving liquids or condensation can cause false touches
– Solid contaminants create non-touch areas until removed
– Doesn't support drag or draw effectively
Capacitive
A capacitive touch screen panel
consists of an insulator such
as glass, coated with a
transparent
conductor
such
as indium tin oxide (ITO). As the
human body is also a conductor,
touching the surface of the screen
results in a distortion of the
body's
electrostatic
field,
measurable
as
a
change
in capacitance.
Advantages & Disadvantages of Capacitive
• Advantages
– Scratch resistant, durable surface
– High endurance (225 million touches)
– Very accurate
– Good optical clarity
– Liquids won't affect touch screen performance
• Disadvantages
– Does not work with gloved fingers or stylus
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 the pattern of LED
beams. Infra-red bezels have
proven to be a very reliable
technology
for
use
in
ATMs,Medical Instrumentation
and Transportation Tracking
applications.
Advantages & Disadvantages of Infrared Touch
Screen
• Advantages
-Highest quality of underlying image
-Very high transmittance
-Excellent anti-glare, with use of chemically etched glass
-Can be activated with almost any device
-Higher accuracy than other technologies
-Very high durability and reliability
• Disadvantages
- Surface obstructions can cause a false touch
–It is very sensitive and can be activated by stray touches.
–Low resolution
–Parallax problems
Touch Screen Technology Comparison Chart
Resistive
Infrared
SAW
Capacitive
Touch
Resolution
High
High
Average
High
Clarity
Average
Good
Good
Good
Operation
Finger or Stylus Finger or Stylus Finger or Softtipped Stylus
Finger only
Durability
Can be
Damaged by
Sharp Objects
Highly durable
Highly Durable
Susceptible to
Dirt and
Moisture
Advantages & Disadvantages of all Touch
Technology
Touch screens have several advantages over other pointing devices:
• A touch screen is easy to use (as the user simply touches what he or
she sees on the display).
• Save space as no buttons are required.
• Touching a visual display of choices requires little thinking and is a
form of direct manipulation that is easy to learn.
• Touch screens are the fastest pointing devices.
• Touch screens have easier hand eye coordination than buttons.
• Touch screens are durable in public access and in high volume usage.
Disadvantages
• 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.
• Touch screen devices usually has no additional keys (see the iPhone)
and this means when an app crashes, without crashing the OS, you
can’t get to the main menu as the whole screen becomes unresponsive.
• Most user interfaces are not optimized for thumb operation, so a
stylus in necessary, and this means using two hands
• Screens get very dirty.
• These devices require massive computing power which leads to slow
devices.
CLOSING THOUGHTS
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.