It describes about all the interactions with touch screen devices.

1. MULTITOUCH INTERACTION
(A PowerPoint Presentation)

2. OVERVIEW
Introduction
Hardware and Software
Natural User Interfaces
Markets and Applications
Types
Gestures
Implementation
Applications
Market trends
Present and Future

3. MULTITOUCH?
“In computing, multi-
touch refers to a touch
sensing surface's (track
pad or touchscreen) ability
to recognize the presence
of two or more points of
contact with the surface.”

4. Introduction
• Multi-touch technology presents a wide
range of new opportunities for interaction
with graphical user interfaces, allowing
expressive gestural control and fluid multi-
user collaboration through relatively simple
and inexpensive hardware and software
configurations.

5. Types
a) Capacitive Touch Technologies
b) Resistive Touch Technologies
c) Optical Touch Technologies
d) SAW Touch Technologies
e) Infrared Technologies

6. Capacitive
Touch Screen
Technology
 A capacitive touch screen
consists of a glass panel
with a capacitive (charge
storing) material coating
its surface. Circuits
located at corners of the
screen measure the
capacitance of a person
touching the overlay.
 But it only responds to
finger contact and will not
work with a gloved hand
or pen stylus.

7. Resistive Touch
Screen Technology
Resistive touch screen
technology consists of a glass or
acrylic panel that is coated with
electrically conductive and
resistive layers. The thin layers
are separated by invisible
separator dots. When operating,
an electrical current moves
through the screen. When
pressure is applied to the screen
the layers are pressed together,
causing a change in the electrical
current and a touch is registered.

8. Surface Acoustic
Wave (SAW)
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.
It uses pure glass
construction, hence SAW
provides superior image
clarity, resolution and higher
light transmission compared
to resistive and capacitive
technologies.

9. Infrared
Infrared technology relies
on the interruption of an
infrared light grid in front
of the display screen. The
touch frame contains a
row of infrared LEDs and
photo transistors, each
mounted on two opposite
sides to create a grid of
invisible infrared light.
The frame assembly
comprises printed wiring
boards, on which the
electronics are mounted
and is concealed behind
an infrared-transparent
bezel.

10. Optical Touch
Optical imaging solution is one of
the more modern touch
technologies.
Since NextWindow's technology
uses optical sensors to detect the
touch point, the touch registers
just before the physical touch on
the screen. This means that users
can apply zero or light touch to
the screen to initiate a response,
and any input device, such as a
paintbrush, finger, pen, or stylus
will work.
Optical imaging provides a
solution without calibration drift.

11. Comparison

12. Multi-touch
Gestures
Tap
Pan
Long press
Scroll
Two finger scroll
Flick
Two finger tap
Pinch open
Pinch close

13. Applications
• Our technique is force-sensitive, and provides
unprecedented resolution and scalability, allowing
us to create sophisticated multi-point widgets for
applications large enough to accommodate both
hands and multiple users.

14. Multi-Touch & Mobile
WHAT WE DID:
 3D and VFX
 Adobe Flash Platform
Development
 Animation
 Information Architecture
 Interface Design
 Microsoft Pixel Sense
Development
 Microsoft Surface Development
 Mobile Design
 Mobile Web Development
 Public Installation
 Sound Design
 Strategy
 Usage Tracking / Analytics
 User Experience Design
 Visual Design

15. A New Approach
Frustrated Total Internal Reflection (FTIR):
• If another material touches that within
which the light is reflecting, the reflection is
frustrated, causing the light to escape.
• This has been used in the past:
• fingerprint imaging
• early touch sensors (1970s!)
• tactile sensors for robotic grips

16. Using FTIR for Touch Sensitivity
• A clear acrylic sheet is used as the touch
surface.
– 16 inches x 12 inches in prototype
• Edges of surface lit by infra-red LEDs to
produce total internal reflection.
• A video camera is mounted under the surface
and facing it.
• When the surface is touched, the light
escapes and registers on the camera.

17. Advantages to this Approach
• High capture rate and resolution
– 30 frames per second
– 640x480
• True zero-force touch sensitivity
• Inexpensive to construct
• Scalable to much larger (even wall-sized!)
surfaces
• Transparent: can be combined with rear-
projection display

18. The current use of multi-touch
technology
 The current use of multi-touch technology enables users to easily interact
with various devices by simply using a touch screen and navigate through
interactive content with ease, ensuring great flexibility and speed.
 Nowadays, users have the opportunity to use multi-touch display panels,
multi-touch displays windows, but also multi-touch tables and notebooks.
 Some important players on the market of multi-touch solutions are Touch
Data LLC and GestureTek who are focused on the development of
comfortable and effective solutions such as the multi-touch wall or multi-
touch workstation.
 Their products and solutions ensure the possibility of simultaneously
accommodating multiple users and individual use. Such solutions are
widely used in professional presentations and for broadcast use due to their
flexibility, speed, effective interactivity and great design.

19. The scope of multi-touch interaction
 The multi-touch solutions will continue to evolve in
complexity and ease of use, and we will be main
beneficiaries of such multi-touch achievements.
 More investments will be made in the field of multi-touch
technology as well as in the research papers conducted by
professional engineers in this area of expertise.
 TouchData LLC. is also planning to revolutionize the
computer era through their multi-touch solutions by
ensuring a 100% natural user interaction with such devices.
Their solutions will be able to be implemented in many
fields such as engineering, tourism, academic, media,
marketing and also medical field.

20. Enhancement in Technology
In more recent work we focus on new multi-touch
paradigms and interactions that combine both traditional 2D
interaction and novel 3D interaction on a touch surface to form
a new class of multi-touch systems, which we refer to as
interscopic multi-touch surfaces (iMUTS). We discuss iMUTS-
based user interfaces that support interaction with 2D content
displayed in monoscopic mode and 3D content usually
displayed stereoscopically.

21. Market Trends
Figure shows the key aspects of
how user interfaces and
interaction technologies have
evolved over the past 50 years:
specifically, an increase in size
and number of units sold,
improvement in degree of
interactivity (from static batch
processing to intuitive interfaces)
and degree of integration with
other devices and technologies.
This evolution marks the
beginning of a transformational
shift, with the user experience
through computing form factors
superseding the effects of
product functionalities.

22. References
• 3Dconnexion, a Logitech company. Spaceball.
• 3Dconnexion, a Logitech company. Spacemouse.
• Anand Agarawala and Ravin Balakrishnan. Keepin’ it real: pushing the desktop
metaphor with physics, piles and the pen. In CHI ’06: Proceedings of the
• SIGCHI conference on Human Factors in computing systems, pages 1283–1292,
New York, NY, USA, 2006. ACM Press.
• David Ahlstroem, Rainer Alexandrowicz, and Martin Hitz. Improving menu
interaction: A comparison of standard, force enhanced and jumping menus. In
CHI ’06: Proceedings of the SIGCHI conference on Human Factors in comput-
ing systems, pages 1067–1076, New York, NY, USA, 2006. ACM Press.

23. Thank you!