Faculty of Engineering – Rabigh
King Abdulaziz University
ABDULMAJEED ABU ALAZ
ABDULMAJEED AL EDRISS
IEN 101 TECHNICAL
SUBMITTED TO: DR. HARISH
We have made this report file on the topic
Touch Screen Technology; we have tried our best to elucidate all the relevant
detail to the topic to be included in the report. While in the beginning we
have tried to give a general view about this topic.
Touch screen technology is a kind of input
innovation that allows people to manipulate a computer system by simply
touching the terminal display screen. Touch screen technology is adapted for a
wide variety of e-business and personal application, such as public information
display, customer self-service, control and automation systems, and computer
based training and personal entertainment. Touch screen technology can be used
with most servers and all personal computers as easily as other peripheral
equipment such as mouse or digital trackball.
TABLE OF CONTENTS
LIST OF FIGURES. 5
WHAT IS TOUCH SCREEN TECHNOLOGY?. 7
HISTORY AND DEVELOPMENT OF TOUCH SCREEN.. 7
WHY USE TOUCH SCREEN.. 12
HOW DOES A TOUCHSCREEN WORK?. 12
Touch Sensor 12
Software Driver 13
TYPES OF TOUCHSCREEN TECHNOLOGY.. 14
Resistive Touchscreen Technology. 14
Capacitive Touchscreen Technology. 15
Surface Acoustic Wave Touchscreen technology. 17
Infrared Touchscreen Technology. 18
APPLICATION OF TOUCH SCREEN.. 18
ADVANTAGES OF TOUCH SCREEN.. 19
DISADVANTAGES OF TOUCH SCREEN.. 19
LIST OF FIGURES
Figure 1 Finger stress. 10
Figure 2 capacitive touchscreen technology. 16
Figure 3 Surface Acoustic Wave Touchscreen technology. 17
Nowadays, we all can frequently see
the Touch Screen applications around our environment. Starting from our pocket
to ATMs, Service counter applications to Information displays, touch screen
technology have been widely used and applied.
is an input and output device normally layered on the top of an electronic
visual display of an information processing system. A user can give input or
control the information processing system through simple or multi-touch
gestures by touching the screen with a special stylus or one or more fingers.
The touchscreen enables the user to interact directly with what is
displayed, rather than using a mouse, touchpad, or any other intermediate
device (other than a stylus, which is optional for most modern touchscreens).
Touchscreens are common in devices such as game consoles, personal
computers, tablet computers, and smartphones. They can also be attached to
computers or, as terminals, to networks. 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 and some
The popularity of smartphones, tablets, and many types of
information appliances is driving the demand and acceptance of common
touchscreens for portable and functional electronics. Touchscreens are found in
the medical field and in heavy industry, as well as for automated teller
machines (ATMs), and kiosks such as museum displays or room automation, where
keyboard and mouse systems do not allow a suitably intuitive, rapid, or
accurate interaction by the user with the display’s content.
Historically, the touchscreen sensor and its accompanying
controller-based firmware have been made available by a wide array of after-market
system integrators, and not by display, chip, or motherboard manufacturers.
Display manufacturers and chip manufacturers worldwide have acknowledged the
trend toward acceptance of touchscreens as a highly desirable user interface
component and have begun to integrate touchscreens into the fundamental design
of their products.
WHAT IS TOUCH
Touchscreen technology is the direct manipulation type gesture
based technology. Direct manipulation is the ability to manipulate digital world
inside a screen without the use of command-line-commands.
A device which works on touchscreen technology is coined as
Touchscreen. A touchscreen is an electronic visual display capable of
‘detecting’ and effectively ‘locating’ a touch over its display area.
It is sensitive to the touch of a human finger, hand, pointed
finger nail and passive objects like stylus. Users can simply move things on
the screen, scroll them, make them bigger and many more.
HISTORY AND DEVELOPMENT OF TOUCH SCREEN
In 1971, the first “Touch Sensor” was developed by Doctor
Sam Hurst (founder of Elographics) while he was an instructor at the University
of Kentucky. This sensor, called the “Elograph,” was patented by The
University of Kentucky Research Foundation. The “Elograph” was not
transparent like modern touch screens; however, it was a significant milestone
in touch screen technology. In 1974, the first true touch screen incorporating
a transparent surface was developed by Sam Hurst and Elographics.
In 1977, Elographics developed and patented five-wire resistive
technology, the most popular touch screen technology in use today. Touchscreens
first gained some visibility with the invention of the computer-assisted
learning terminal, which came out in 1975 as part of the PLATO project.
Touchscreens have subsequently become familiar in everyday life. Companies use
touch screens for kiosk systems in retail and tourist settings, point of sale
systems, ATMs, and PDAs, where a stylus is sometimes used to manipulate the GUI
and to enter data. The popularity of smart phones, PDAs, portable game consoles
and many types of information appliances is driving the demand for, and
acceptance of, touchscreens.
From 1979–1985, the Fair light CMI (and Fair light CMI IIx) was a
high-end musical sampling and re-synthesis workstation that utilized light pen
technology, with which the user could allocate and manipulate sample and
synthesis data, as well as access different menus within its OS by touching the
screen with the light pen. The later Fair light series III models used a
graphics tablet in place of the light pen.
The HP-150 from 1983 was one of the world’s earliest commercial
touchscreen computer. It did not have a touchscreen in the strict sense;
instead, it had a 9″ Sony Cathode Ray Tube (CRT) surrounded by infrared
transmitters and receivers, which detected the position of any non-transparent
object on the screen.
Until recently, most consumer touchscreens could only sense one
point of contact at a time, and few have had the capability to sense how hard
one is touching. This is starting to change with the commercialization of
Touchscreens are popular in hospitality, and in heavy industry, as
well as kiosks such as museum displays or room automation, where keyboard and
mouse systems do not allow a suitably intuitive, rapid, or accurate interaction
by the user with the display’s content.
Historically, the touchscreen sensor and its accompanying
controller-based firmware have been made available by a wide array of
after-market system integrators, and not by display, chip, or motherboard
manufacturers. Display manufacturers and chip manufacturers worldwide have
acknowledged the trend toward acceptance of touchscreens as a highly desirable
user interface component and have begun to integrate touchscreen functionality
into the fundamental design of their products.
Virtually all of the significant touchscreen technology patents
were filed during the 1970s and 1980s and have expired. Touchscreen component
manufacturing and product design are no longer encumbered by royalties or
legalities with regard to patents and the manufacturing of touchscreen-enabled
displays on all kinds of devices is widespread.
The development of multipoint touchscreens 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 growing acceptance of many kinds of products with an
integral touchscreen interface, the marginal cost of touchscreen technology is
routinely absorbed into the products that incorporate it and is effectively
eliminated. As typically occurs with any technology, touchscreen hardware and
software has sufficiently matured and been perfected over more than three
decades to the point where its reliability is proven. As such, touchscreen
displays are found today in airplanes, automobiles, gaming consoles, machine
control systems, appliances, and handheld display devices of every kind. With
the influence of the multi-touch enabled iPhone, the touchscreen market for
mobile devices is projected to produce US$5 billion in 2009.
The ability to accurately point on the screen itself is also
advancing with the emerging graphics tablet/screen hybrids.
Figure 1 Finger stress
An ergonomic problem of touchscreens is their stress on human
fingers when used for more than a few minutes at a time, since significant
pressure can be required for certain types of touchscreen. This can be
alleviated for some users with the use of a pen or other device to add leverage
and more accurate pointing. The introduction of such items can sometimes be
problematic, depending on the desired use (e.g., public kiosks such as
A.T.M.s). Also, fine motor control is better achieved with a stylus, because a
finger is a rather broad and ambiguous point of contact with the screen itself.
WHY USE TOUCH SCREEN
· Enable first-time users to interface with computers instantly,
without any training.
· Eliminate operator errors because users make selections from
clearly defined menus.
· Eliminate keyboards and mice, which many novice users find
difficult to use.
· Rugged enough to stand up to harsh conditions where keyboards and mice
can be damaged.
· Provide fast access to all types of digital content.
· Ensure that no space is wasted since the input device is completely
integrated into the monitor.
HOW DOES A TOUCHSCREEN WORK?
A basic touchscreen has three main components: a touch sensor,
a controller, and a software driver. The touchscreen is an input
device, so it needs to be combined with a display and a PC or other device to
make a complete touch input system.
A touch screen sensor is a clear glass panel with a touch
responsive surface. The touch sensor/panel is placed over a display screen so
that the responsive area of the panel covers the viewable area of the video
screen. There are several different touch sensor technologies on the market
today, each using a different method to detect touch input.
The sensor generally has an electrical current or signal going
through it and touching the screen causes a voltage or signal change. This
voltage change is used to determine the location of the touch to the screen.
The controller is a small PC card that connects between the touch
sensor and the PC. It takes information from the touch sensor and translates it
into information that PC can understand. The controller is usually installed
inside the monitor for integrated monitors or it is housed in a plastic case
Tor external touch addÃ‚Â¬ons/overlays.
The controller determines what type of interface/connection you
will need on the PC. Integrated touch monitors will have an extra cable
connection on the back for the touchscreen. Controllers are available that can
connect to a Serial/COM port (PC) or to a USB port (PC or Macintosh).
Specialized controllers are also available that work with DVD players and other
The driver is a software update for the PC system that allows the
touchscreen and computer to work together. It tells the computer’s operating
system how to interpret the touch event information that is sent from the
Most touch screen drivers today are a mouse-emulation type driver.
This makes touching the screen the same as clicking your mouse at the same
location on the screen. This allows the touchscreen to work with existing
software and allows new applications to be developed without the need for
touchscreen specific programming.
Some equipment such as thin client terminals, DVD players, and
specialized computer systems either do not use software drivers or they have
their own built-in touch screen driver.
TYPES OF TOUCHSCREEN TECHNOLOGY
Let us now give
an engineer’s eye to this revolutionary technology. A touchscreen is a 2
dimensional sensing device made of 2 sheets of material separated by spacers.
There are four main touchscreen technologies:
Resistive Touchscreen Technology
A resistive touchscreen 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: the panel then behaves as a pair of voltage dividers with connected
outputs. This causes a change in the electrical current which is registered as
a touch event and sent to the controller for processing.
In another way 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,
much as a computer mouse driver translates a mouse’s movements into a click or
The Capacitive Touchscreen Technology is the most popular and
durable touchscreen technology used all over the world at most. It consists of
a glass panel coated with a capacitive (conductive) material Indium Tin Oxide
(ITO). The capacitive systems transmit almost 90% of light from the monitor.
Some of the devices using capacitive touchscreen are Motorola Xoom, Samsung
Galaxy Tab, Samsung Galaxy SII, Apple’s iPad. There are various capacitive
technologies available as explained below.
Surface-Capacitive screens, in this technique only one side of the
insulator is coated with a conducting layer. While the monitor is operational,
a uniform electrostatic field is formed over the conductive layer. Whenever, a
human finger touches the screen, conduction of electric charges occurs over the
uncoated layer which results in the formation of a dynamic capacitor. The
computer or the controller then detects the position of touch by measuring the
change in capacitance at the four corners of the screen.
Pros and Cons:
surface capacitive touchscreen is moderately durable and needs calibration
during manufacture. Since a conductive material is required to operate this
screen, passive stylus cannot be used for surface capacitive touchscreen.
Projected-Capacitive Touchscreen Technology, the conductive ITO layer is etched
to form a grid of multiple horizontal and vertical electrodes. It involves
sensing along both the X and Y axis using clearly etched ITO pattern.
The projective screen contains a sensor at every intersection of
the row and column, thereby increasing the accuracy of the system. There are
two types of projected capacitive touchscreen: Mutual Capacitance and Self
Surface Acoustic Wave
The Surface Acoustic Wave Touchscreen technology contains two
transducers (transmitting and receiving) placed along the X-axis and Y-axis of
the monitor’s glass plate along with some reflectors. The waves propagate
across the glass and are reflected back to the sensors. When the screen is
touched, the waves are absorbed and a touch is detected at that point. These
reflectors reflect all electrical signals sent from one transducer to another.
This technology provides excellent throughput and image clarity.
100% clarity is obtained as
no metallic layers are present on the screen, it can be operated using passive
devices like stylus, glove or finger nail. Screen can get contaminated with
much exposure to dirt, oil which may haunt its smooth functioning.
Figure 3 Surface Acoustic Wave Touchscreen
In the Infrared Touchscreen Technology, an array of X- and Y- axes
are fitted with pairs of IR Led and photo detectors. The photo detectors detect
any change in the pattern of light emitted by the Led whenever the user touches
APPLICATION OF TOUCH SCREEN
/ tourism displays
Wide Web access kiosks
and other gaming systems
· Computer access for the physically disabled
ADVANTAGES OF TOUCH SCREEN
· Switch and buttons are not physically required. Device makers can
make and modify various input interfaces creatively by software.
· With multi-touch function, various operations/inputs (e.g.:
zoom-in/zoom-out, rotation) are possible.
· Because a user operates an electronic device by directly touching
the images on the display he is seeing, the operation will be intuitive, thus
anyone can operate it from first use.
· The whole unit is space-saving because display and input space are
integrated. There is a lot of flexibility in design.
· Unlike keyboard or physical switch, there will be no dirt, dust,
and moisture getting into the spaces between buttons. Thus, it is easy for
DISADVANTAGES OF TOUCH SCREEN
· Screen has to be really big not to miss things when pressing them
with your finger: I only like HTC Touch HD, screen size wise, and big screen
means increased size of the device.
· Big screen leads to low battery life.
· Touchscreen means screen can’t be read too well in direct sunlight
as it applies an additional not 100% transparent.
· Touchscreen 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.
· Touchscreens usually have low precision, virtual QWERTY keyboards
being one of the most annoying things.
· 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 and low battery life.
represent a rapidly growing subset of the display market. The majority of touch
systems include touch sensors relying on vacuum-deposited coatings, so touch
coatings present opportunity for suppliers of vacuum coatings and coating equipment.
manufactures currently require thin films in the areas of transparent
conductors, optical interference coating and mechanical protective coatings.
Touch sensors technical requirements dovetail well with those of the flat panel
and display filter markets. The reality should provide value added
opportunities to operations participating in these areas.