Transcript TOUCH SCREEN TECHNOLOGY PRESENTED BY •Priya Mishra •Saroj Singh •Shikha Ghodeshwar INTRODUCTION  Works with the principle of CRT (Cathode Ray Tube) technology.  Input device --> Operates a PC.

TOUCH SCREEN TECHNOLOGY
PRESENTED BY
•Priya
Mishra
•Saroj Singh
•Shikha Ghodeshwar
INTRODUCTION

Works with the principle of CRT (Cathode Ray
Tube) technology.

Input device --> Operates a PC by simply
touching the display screen.

Made of sensitive glass overlay & desired inputs
can be given by touching it.

Inputs --> External (light pen) or an internal
device (touch overlay and controller) .
COMPONENTS OF TOUCH SCREEN

Three major components viz,

Touch sensor

Controller

Software driver
TOUCH SENSORS
Touch
sensor
Covering screen
CONTD..

Touch sensor --> In between clear glass panels.

Responsive area --> Entire viewable area of the
display screen.

Sensors --> Detects electrical current or signal.

Touching -->causes a voltage or signal change,
thereby the location can be determined.
CONTROLLER
CONTD…

PC card --> Touch sensor and the PC.

Change in voltage --> Translated into the
information that CPU understands.

Translated bits --> Position where the touch
occurs.

Processor --> change the screen accordingly.
SOFTWARE DRIVER

Acts as a bridge --> Screen and processor.

Makes the operating system --> To interpret the
touch event information.

Touch screen drivers today --> Mouse-emulation
type driver ( like touching the screen the same
as clicking mouse)

Recent research --> To make it as PNP
TYPES OF TOUCH SCREEN

Resistive Touch screen

Surface wave Touch screen

Capacitive Touch screen
Surface capacitive
 Projected capacitive


Infrared Touch screen
RESISTIVE TOUCH
SCREENS
RESISTIVE TOUCH SCREEN
CONTD…

1. Polyester Film.

2. Top Resistive Layer.

3. Conductive Transparent Metal Coating.

4. Bottom Resistive Layer .

5. Insulating Dots .

6. Glass Substrate
WORKING OF RESISTIVE
SENSORS

Resistive touch screen monitor composed of :
 Flexible top layer
 Rigid bottom layer
 Insulating dots
 Along with touch screen controller.

Top & Bottom layers --> transparent metal oxide coating.

Pressure over the flexible top sheet --> Makes electrical
contact between the resistive layers & the switch closing in
the circuit.

Controller --> Alternating voltages & converts them into
the digital X and Y coordinates.
CONTROLLER

NAME:


Supply Voltage


5.0V DC
Maximum Current


VS20UA CONTROLLER
20mA
Resolution

12-bit
PROPERTIES
2
conductive layers that connects when touched.
 Capable
 Not
of multi touch.
affected by dirt or dust.
 Good
for outdoor use.
SURFACE WAVE TOUCH
SCREEN
SURFACE WAVE TOUCH SCREEN
WORKING OF SURFACE WAVE
SENSORS

Contains Transmitting and receiving transducers

Touchscreen controller --> 5 MHz electrical signal to the
transmitting transducer.

Converts electrical signal --> ultrasonic waves within the
glass.

Waves --> Directed across the front surface of screen.

Reflectors - -> Reflects & directs towards receiving
transducer.

Receiving transducer --> reconverts --> An electrical signal
& digitally maps the touchscreen
CONTROLLER

NAME:


Voltage


9600
Touch Resolution


+5 VDC
Baud Rate


2701RSU CONTROLLER
12bit, size independent
Conversion Time

10 ms per coordinate set
CAPACITIVE TOUCHSCREEN
CAPACITIVE TOUCHSCREEN
WORKING OF CAPACITIVE
TOUCHSCREEN

Uniform conductive coating on a glass panel.

Operation --> Electrodes around the panel's
edge evenly distribute a low voltage across the
conductive layer & creates an uniform electric
field.

Finger touch --> Draws current from each corner.

Controller --> Measures ratio of the current flow
from the corners & calculates the touch location.

Capacitance --> Finger and the sensor grid.
LAYERS OF CAPACITIVE
TOUCHSCREEN

Contains 3layers ,viz

Front Protective glass

Back protective glass
- provides optical & strength enhancement options

Middle layer
- laminated sensor grid of micro-fine wires
CONTROLLER

Name:


Supply Voltage:


9600 (default) and 19200
Touch Resolution


+5 V DC or +12V
Baud Rate


5000 RSU SERIAL
CONTROLLER
12bit, size independent.
Conversion Time

Approximately 15 ms
per coordinate set
PROPERTIES

Conductive coating that emits electric field.

Very durable.

Must be touched by some conductive materials.

Capable of multi touch.
PROS & CONS OF TOUCH
SCREENS
PROS

Direct pointing to the
objects.

Fast.

CONS

Low precision when we
use finger.

Screen may be covered
more by using hand

No direct activation to the
selected function
Finger or pen is usable
(No cable required)

No keyboard necessary

Suited to all interactive
applications.
APPLICATIONS

Public Information Displays:::




Customer Self-Services:::





Tourism displays
Trade show display
Awareness kiosks
General departmental Stores
Restaurants
ATMs
Airline ticket terminals, etc.
Other uses:::



Digital jukeboxes
Computerized gaming
Student Registration systems, etc.
RECENT PRODUCT S
UNDER DEVELOPEMENT
RECENT TRENDS

Introduction of

i-PAN7: Flat Touchscreen
computer - Panel PC

Introduced by Keith &
Koep of Japan.

Small frame computer.

Runs with Windows
Embedded CE & built
with low power ARM
processor.

Uses Capacitive touch
panels.
CONCLUSION

Though the Touch screen technology contains
some limitations it’s
user friendly.
 Fast.
 Accurate.
 easy to operate.


It has been widely accepted and a little
modification can replace the mouse and key
board completely in near future.
THANK YOU