Multi-touch technology allows for multiple touch points on a touch screen. Early versions from the 1980s supported two fingers, while modern technology can support up to 20 fingers. Multi-touch was introduced on the iPhone in 2007 and later used in other Apple products like the MacBook. It works using frustrated total internal reflection, where infrared light and cameras detect touch points. Advantages include low cost and support for high-resolution graphics. Applications include personal computers, tablets, phones, and advanced gaming.

1. LESLEY.S
Reg. No.SBAG10183781
MULTI TOUCH

2. • A touch screen is a display
which can detect the presence
and location of a touch
within the display area.
• One point of contact at a
time.

3. • Multi-touch technology is an advanced
human-computer interaction technique
that recognises multiple touch points and
also includes the hardware devices that
implement it.
• which allow users to compute without
conventional input devices .

4. • Multi-touch technology dates back to 1982, when
the University of Toronto developed the first
finger pressure multi-touch.
• In 1984 Bell Labs engineered a multi-touch
screen that could manipulate images with more
than one hand.
• In1991 Wellner published a paper on his multi-
touch “Digital Desk”, which supported multi-
finger and pinching motions.
History of Multi Touch…

5. In 2007 Microsoft introduced
Microsoft Surface.
Intel Core 2 Duo processor,
Windows Vista, and 2 GB of RAM.

7. • PP is a company founded by New York
University consulting research
scientist Jefferson Y. Han that creates
wall displays and tables.
• It can accommodate up to 20 fingers.

8. In 2007 they introduced the iPhone, marking
the first time multi-touch technology was used on
a phone.
Later on this technology was introduced in iPod
touch, MacBook Air, and MacBook Pro.

9. MacBook Pro
iPhone Touch
iPod touch
MacBook Air

10. IR rays obtained on a camera

11. F T I R
F R U S T R A T E D T O T A L I N T E R N A L
R E F L E C T I O N
• Total internal reflection is an optical phenomenon that occurs when a ray
of light strikes a medium boundary at an angle larger than the critical
angle with respect to the normal to the surface.
• The critical angle is the angle of incidence above which total internal
reflection occurs.
• The critical angle is given by:
n2= Refractive index of the less dense medium.
n1= Refractive index of the denser medium.

12. Total Internal Reflection

13. (a) IR view of a touch(b)Pixel positions located on screen
Frustrated Total Internal Reflection

14. Acrylic with led’s at its edges

15. IR led’s Acrylic Camera Projector Computer

16. Processing
(P5)
Flash C C++ Java

17. ADVANTAGES
• Low cost factor.
• Support high-resolution graphics.
• Larger shared-display systems.
• It acquires true touch image
information at high spatial and
temporal resolutions.

18. APPLICATION
• Personal computers, Laptops ,Tabletops ,
Graphics Tablets .
• It supports both LCD and CRT monitors .
• Telephones ,Watches ,PDAs, Mobile phones.
• Advanced multi touch Gaming with high graphics
support.
• Governmental, office and business purposes.

19. • Multi-touch technology is an advanced human-computer
interaction technique, which allow users to compute without
conventional input devices .

21. THANK
YOU