7/27/2019 Introduction to Touch Screens
1/29
Seminar
Touch screen Technology
By
Junaid Shah
Enr No. 110229MSc IT -Semester I
Teacher In charge
Mr. Aasif Ali Banka
7/27/2019 Introduction to Touch Screens
2/29
OVERVIEW
1. Introduction.
2. History.
3. Types.4. Capacitive Touch Screen in Detail.
7/27/2019 Introduction to Touch Screens
3/29
INTRODUCTION
A touch screen is an Electronic Visual Display
that can detect the presence and location of atouch within the display area and respond
accordingly.
7/27/2019 Introduction to Touch Screens
4/29
HISTORY
The first touch screen was acapacitive touch screendeveloped by E.A. Johnsonat the Royal Radar
Establishment, Malvern, UKin 1965.
In 1971, the first "TouchSensor" was developed byDoctor Sam Hurst (founder
of Elographics) while he wasan instructor at theUniversity of Kentucky.
7/27/2019 Introduction to Touch Screens
5/29
Components in General
A basic touch screen has three main
components :
Touch sensor
Controller
Software driver
7/27/2019 Introduction to Touch Screens
6/29
Touch Sensor
A touch screen sensor is aclear glass panel with a
touch responsive area.
The touch sensor isplaced over a display
screen so that the
responsive area of the
panel covers the viewable
area of the screen.
7/27/2019 Introduction to Touch Screens
7/29
Controller
The controller is the actual hardware circuitrythat connects between the touch sensor anddrivers.
Take information from the touch sensor and
translate it into information that PC/device canunderstand.
7/27/2019 Introduction to Touch Screens
8/29
Software Driver
The driver allows the touch screen and
computer to work together as an interface.
This makes touching the screen as same asclicking the your mouse at the same location
on the screen.
7/27/2019 Introduction to Touch Screens
9/29
Different Technologies of Touch
Screens
1. Resistive Touch Screen,
2. Surface Acoustic Wave Touch Screen,
3. Infra Red Touch Screen,
4. Capacitive Touch Screen.
7/27/2019 Introduction to Touch Screens
10/29
Resistive Touch Screen
A resistive touch
screen panel is
composed of two
thin, electrically
conductive layers
separated by a
narrow gap.
7/27/2019 Introduction to Touch Screens
11/29
Surface Acoustic Wave Touch Screen
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
7/27/2019 Introduction to Touch Screens
12/29
Infra Red Touch Screen
An infrared touch screenuses an array of X-Yinfrared LED and photo-detector pairs around theedges of the screen todetect a disruption in thepattern of LED beams.
These LED beams crosseach other in vertical and
horizontal patterns. Thishelps the sensors pick upthe exact location of thetouch.
7/27/2019 Introduction to Touch Screens
13/29
Capacitive Touch Screen
A capacitive touch screen panel consists ofan insulator such as glass, coated with atransparent conductor such as Indium Tin
Oxide (ITO).As the human body is also an electricalconductor, touching the surface of the screenresults in a distortion of thescreen's electrostatic field, measurable as achange in capacitance.
7/27/2019 Introduction to Touch Screens
14/29
Overview of Capacitive touch Sensing
7/27/2019 Introduction to Touch Screens
15/29
7/27/2019 Introduction to Touch Screens
16/29
7/27/2019 Introduction to Touch Screens
17/29
7/27/2019 Introduction to Touch Screens
18/29
CONSTRUCTION OF CAPACITIVE
TOUCH SENSOR
7/27/2019 Introduction to Touch Screens
19/29
7/27/2019 Introduction to Touch Screens
20/29
7/27/2019 Introduction to Touch Screens
21/29
7/27/2019 Introduction to Touch Screens
22/29
7/27/2019 Introduction to Touch Screens
23/29
7/27/2019 Introduction to Touch Screens
24/29
7/27/2019 Introduction to Touch Screens
25/29
7/27/2019 Introduction to Touch Screens
26/29
7/27/2019 Introduction to Touch Screens
27/29
7/27/2019 Introduction to Touch Screens
28/29
Software ReceptionThe software then feeds this
frequency change due to change in
Time Constant and then feeds this
data to an algorithm which in turn
makes the requisite logical action.
7/27/2019 Introduction to Touch Screens
29/29
?
Top Related