This document provides an overview of different touchscreen technologies, including their pros and cons. It explains that resistive, surface acoustic wave, infrared beam break, surface capacitive, and projective capacitive are the major touch technologies used today. Each technology is described in terms of its construction, traits, and strengths and weaknesses compared to other technologies. The document concludes by comparing Baanto's ShadowSense touch technology to the other major technologies, highlighting how it improves on their limitations.

1. Touchscreen
Overview including all
Touchscreen Technologies
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2. Aims of this presentation
• To show where touch is used
• To explain why there are so many different ways to do
the same thing
• To give an understanding of the major touch
technologies that exist in products today
• To understand the pros and cons of each technology
• To show how the Baanto™ ShadowSense™ technology
compares against each technology in turn.

3. Why do we use touch?
Simply put, it makes life easier by implementing a simple
interface to complex machines across many applications
and markets

4. Why do we use touch?
• A touchscreen is simply a piece of hardware used to
emulate a mouse when running applications
• But a touchscreen offers a much better interface to the
public than the mouse and keyboard
• It’s;
– More intuitive in use
– Faster to use
– Rugged
– Does not need an outside light source
– Harder to steal than keyboard and mouse
– Simply looks better

5. Why do we use touch?
They are everywhere!

6. So what is a touchscreen?
A touchscreen tends to be
an overlay placed in front of
a display, made of glass or
certain types of plastic,
which, in a variety of ways,
can convert a pointing
device (e.g. a finger) into X
and Y co-ordinates for
mouse emulation that can
be used by a computer
program to achieve a
desired goal.
A touchscreen cannot do
this alone. It needs a
controller to convert the
touch generated signals into
a form that can be sent to a
computer and traditionally,
some software
to do something
useful with these
signals.

7. So what is a touchscreen?
With the Baanto™ mid-sized
ShadowSense™ technology, a
production kit consists of a
touch frame, cables and a
controller.
What you don’t get is any
software; including calibration
software as ShadowSense™
just doesn't need it!
ShadowSense™ is designed to
work with Win XP, Win XPe,
Vista, Win 7, Win 8, Linux and
Mac OS ‘out of the box’
Baanto’s ShadowSense™ works
simply by plugging the USB
cable into your computer –
that’s all.

8. History of touch technologies
• Touch was invented in the late 60’s by E.A. Johnson at the Royal
Radar Establishment, Malvern, UK
• First real use was developed by Doctor Sam Hurst founder of
Elographics (now EloTouch) while he was an instructor at the
University of Kentucky.
• Lots of changes since then
• Today, there are around 25 fundamentally different touch
technologies that exist worldwide (this number is growing all the
time), however only a few are commercially useful
• In mainstream applications around 5 different types are used in
large volumes

9. Why so many technologies?
Why are there so many different technologies to do such a simple
thing? Quite simply, no touch technology is perfect for all users;
They all have pros and cons!
• It is choosing the right screen for the right environment that
makes the difference between a successful project and a failed
project
• This is why many suppliers have to offer several different types
of screens to their customers as they don’t have ShadowSense™
• YOU must understand the strengths AND the weaknesses of
each technology to be able to explain it to your customer
• If you don’t tell them up front what these are, others will!

10. Why so many technologies?
All touchscreens work well on your desk. Its as you move away from
this and into the real world that you start to see environmental and
usability issues come to light
Key considerations:
• Who will be touching the screen? (employee or public-access)
• How will they touch it? (finger, pen, bankcard, glove, etc.)
• How secure is the environment? (potential for vandalism)
• How long will the screen be in service? (lifetime, stability)
• How important is optical performance? (desired clarity and
brightness)
• What are the ambient lighting conditions? (do you need to
avoiding glare, reflections and sunlight’s effect on the
touchscreen operation)?
• How exposed is the screen to weather and temperature
change? Is it waterproof?

11. So what's out there?
Baanto’s ShadowSense™ is not a revamp of an existing technology.
It is unique in both ethos and operation hence the fact that we
have been granted patents on the technology with several more
in the pipe line.
The other Major Technologies are;
• Resistive (4/7/8 and 5/6 wire)
• Surface Acoustic Wave
• Infra Red (Beam Break Technology)
• Surface Capacitive
• Projective Capacitive

12. Resistive

13. Resistive
Basically the first to be invented (some dispute this with IR) at the
beginning of the 1970,s
Resistive screens come in several flavours
4 wire, 5 wire, 6 wire, 7 wire and 8 wire
Although they do the same basic job, they have very different
properties and the extra wires are there to correct issues with
the technology

14. Resistive screen construction
• Normally, consists of a glass sheet with a conductive surface
usually ITO (Indium Tin Oxide)
On top of this is a
plastic sheet with the
inside surface again
coated with ITO.
Keeping the two
surfaces apart are rows
and columns of ‘spacer
dots’
The voltage generated by the touch is sent to a controller which
sends the result to the computer

15. So what sort of Resistive screen do I have?
With so many different resistive types, a common question is ‘what
kind do I have’?
Simple answer; count the lines in the tail that go to the controller
connector
4 wire Touchscreen
8 wire Touchscreen

16. Resistive traits (Generic)
Pros Resistive Cons Resistive
Can be sealed to IP65 Reduces light transmission by 20% (more for
6 wire)
Works when wet Not vandal proof - easy to damage
Stable Calibration Linearity of 4 wire degrades with time
(short time)
Reasonably simple to integrate Original patent expired allowing cheaper,
poorer quality product to come in from the
far east
Fast touch/drag response Many controller manufactures – not all
good
Works with any pointer Software from many sources not all reliable
High resolution allows for signatures

17. Surface Acoustic Wave (SAW)

18. SAW
Sound wave is deflected across the screen. Touch pointer (finger)
absorbs some of this energy which is detected by the controller
X Transmit ~
5 µsec
5.53 MHz
tone burst
from
controller
X Receive ~ 200 µsec echo signal to controller’s
receive circuitry
Reflector Arrays
Active
Area
Absorption
tape
Y Receive
Y Transmit
Generic Surface Acoustic Wave Operation

19. • Reflectors printed on glass
• Specific pattern differs with size and type glass
• Reflection from each stripe is about 1%
• Progressively less energy as wave travels across the glass, so
reflector spacing designed to equalize reflected energy across
entire touchscreen (logarithmic)
SAW

20. SAW
Burst of energy sent to the transducers, the transducers convert the
energy to vibration energy which is deflected across the screen by the
reflectors. Energy absorbing pointer removes some of the received signal
allowing detection.
Amplitude
Response
Time
Threshold
Touch Effect
Width
Checked
Z ratio
Time
proportional
to distance
Transmit
Burst

21. SAW Traits
Pros SAW Cons SAW
Clear glass (92% light through put) Hard to seal; needs special material called
volara tape or special rubber
Touch operation Impervious to scratches Cannot be sealed to IP65 reliably
Reasonably fast touch response Stops working when wet
Works with gloved hands Complex to integrate for the first time users
Only works with a soft pointer (no stylus,
fingernails, pens or credit cards)
Not good at finger dragging or signature
writing
Original patent expired allowing cheaper,
poorer quality product to come in from the
far east

22. Infrared (Beam Break Technology)

23. Infrared (Beam Break Technology)
• The touch frame or opto-matrix
contains a row of IR-light-
emitting diodes (LEDs) and a
row of photo transistors
(receivers), mounted on
opposite sides to create and
detect a grid of invisible infrared
light.
• When a stylus, such as a finger,
enters the grid, it obstructs the
beams.
• One or more photo transistors
detects the absence of light and
transmits a signal that identifies
the x and y coordinates.
Transmit Photodiodes
Receive Phototransistors
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24. Infrared (Beam Break Technology)
Pros IR (Beam Break) Cons IR (Beam Break)
Clear glass (92% light through put) Lower resolution than other technologies
Touch operation Impervious to scratches Can be effected by Sunlight
Calibration setup never drifts after set up ‘Fly on screen’ false touches
Low touch force sensitivity (hover) Original patent expired allowing cheaper,
poorer quality product to come in from the
far east
Reasonably fast touch response
Works with almost any pointer if large
enough to block the light

25. Capacitive (Surface)

26. Capacitive (Surface)
• Its like a Resistive screen without the top plastic cover
• A hard coating is applied over the conductive ITO layer to help
protect it from scratches

27. Capacitive (Surface)
Pros Surface Capacitive Cons Surface Capacitive
Easy to integrate Can be effected by rain water (these days
this is acidic)
Impervious to ‘water’ (tap or river water) Can be relatively easily scratched destroying
linearity
Fast touch and drag response Calibration can be affected by a number of
mechanisms
Original patent expired allowing cheaper,
poorer quality product to come in from the
far east
Needs a conductive pointer (no pens, credit
cards etc.)

28. Projective Capacitive (wire)

29. Projective Capacitive (wire)
• Screen is made up of several layers
• Older screens had controller
mounted on the glass
• Embedded wires have a set
frequency passed through them
which generates a field around the
wire.
• When an object enters the field, it
changes this frequency which in
turn is transmitted to the computer
where the application detects the
change and works out where the
touch point is.

30. Projective Capacitive (wire)
The advantage that this technology offers is the ability to work
through several mm’s of non conductive material such as a shop
window.
This gives all sorts of possibilities for vandal and weather proof
outdoor kiosks

31. Projective Capacitive (wire)
Pros Projective Capacitive Cons Projective Capacitive
Works through gloves Can be very slow to respond
Works through non conductive material up
to 25mm (it’s main reason for existence)
Can be affected by electromagnetic
interference from LCD’s and neon lights and
others
Due to use of sacrificial glass in front of the
touch technology, can be very robust
Complex to integrate and set up
Does not work through any metallised
coatings (such as heat reflective glass)
Active area must be kept at least 2mm away
from metal (Active area is the whole surface
of the sensor)
Can go out of calibration due to may
different environmental conditions.

32. Baanto’s ShadowSense™ v The Rest
The following slides show how Baanto’s patented ShadowSense™
technology compares against the other major single
Touch technologies
on the market today

33. Resistive Pros v ShadowSense™
ShadowSense™ has most of the Pros of Resistive
Pros Resistive ShadowSense™
Can be sealed to IP65 Can be sealed to IP65
Works when wet Works when wet
Stable Calibration Stable calibration for the life of the product
Reasonably simple to integrate Simple to integrate on Open frame chassis
Fast touch/drag response Fast touch/drag response
Works with any pointer Works with any pointer
High resolution allows for signatures High resolution allows for signatures

34. Resistive Cons v ShadowSense™
ShadowSense™ has none of the Cons of Resistive
Cons Resistive ShadowSense™
Reduces light transmission by 20% (more for
6 wire)
Excellent light transmission 92% or more
Not vandal proof - easy to damage Highly robust
Linearity of 4 wire degrades with time (short
time)
Stable for the life of the product
Original patent expired allowing cheaper,
poorer quality product to come in from the
far east
Unique NEW technology with newly granted
patent protection
Many controller manufactures – not all good All hardware design and controlled in house
by Baanto
Software from many sources not all reliable No software needed, controller firmware
designed and controlled in house by Baanto

35. SAW Pros v ShadowSense™
ShadowSense™ has all the Pros of SAW
Pros SAW ShadowSense™
Clear glass (92% light through put) Excellent light transmission 92% or more
Touch operation Impervious to scratches Highly robust
Reasonably fast touch response Fast 6ms to 8ms response time
Works with gloved hands Works with many pointing devices including
gloves

36. SAW Cons v ShadowSense™
ShadowSense™ has almost none of the Cons of SAW
Cons SAW ShadowSense™
Hard to seal; needs special material called
volara tape or special rubber
Simple to seal
Cannot be sealed to IP65 reliably Comes sealed to IP65
Stops working when wet No problem working when wet
Complex to integrate for the first time users Simple to integrate on Open frame chassis
Only works with a soft pointer (no stylus,
fingernails, pens or credit cards)
Works with any pointer including soft and
hard ones
Not good at finger dragging Fast reliable drag response
Original patent expired allowing cheaper,
poorer quality product to come in from the
far east
Unique NEW technology with newly granted
patent protection

37. IR (Beam Break) Pros v ShadowSense™
ShadowSense™ has all the Pros of IR (Beam Break)
Pros IR (Beam Break) ShadowSense™
Clear glass (92% light through put) Excellent light transmission 92% or more
Touch operation Impervious to scratches Highly robust
Calibration setup never drifts after set up Stable for the life of the product
Low touch force sensitivity (hover) Low touch force that is adjustable
Reasonably fast touch response Fast 6ms to 8ms response time
Works with almost any pointer if large
enough to block the light
Works with almost any pointer

38. IR (Beam Break) Cons v ShadowSense™
ShadowSense™ has none of the Cons of IR (Beam Break)
Cons IR (Beam Break) ShadowSense™
Lower resolution than other technologies Resolution matches Resistive technology
Can be effected by Sunlight Only one side with sensors so affected less
than IR (Beam Break) with other safeguards
to allow working in bright sunlight
‘Fly on screen’ false touches Size of touching object can be ‘gated’ to only
allow touch of a certain size
Original patent expired allowing cheaper,
poorer quality product to come in from the
far east
Unique NEW technology with newly granted
patent protection

39. Capacitive (Surface) Pros v ShadowSense™
ShadowSense™ has most of the Pros of Surface Capacitive
Pros Surface Capacitive ShadowSense™
Easy to integrate Simple to integrate on Open frame chassis
Impervious to ‘water’ can have problems
with rain
No problem working when wet
Fast touch and drag response Fast 6ms to 8ms response time

40. Capacitive (Surface) Cons v ShadowSense™
ShadowSense™ has none of the Cons of Surface Capacitive
Cons Surface Capacitive ShadowSense™
Can be effected by rain water (acidic) No problem working when wet or with rain
Can be relatively easily scratched destroying
linearity
Highly robust
Calibration can be affected by a number of
mechanisms
No User calibration to perform. No drift for
the life of the product
Original patent expired allowing cheaper,
poorer quality product to come in from the
far east
Unique NEW technology with newly granted
patent protection
Needs a conductive pointer (no pens, credit
cards etc.)
Works with any pointing devices including
gloves, pens, credit cards paint brushes etc.

41. Pro. Capacitive (Wire) Pros v ShadowSense™
ShadowSense™ has almost all the Pros of Projective Capacitive
Pros Projective Capacitive (wire) ShadowSense™
Works through gloves Works with almost any pointer
Works through non conductive material up
to 25mm (it’s main reason for existence)
ShadowSense™ will not work through extra
layers of glass
Due to use of sacrificial glass in front of the
touch technology, can be very robust
Highly robust

42. Pro. Capacitive (Wire) Cons v ShadowSense™
ShadowSense™ has almost none of the Cons of Projective Capacitive
Cons Projective Capacitive ShadowSense™
Can be very slow to respond Fast 6ms to 8ms response time
Can be affected by electromagnetic
interference from LCD’s and neon lights and
other external sources
Not affected my external electrical
interference
Complex to integrate and set up Simple to integrate on Open frame chassis
Does not work through any metallised
coatings (such as heat reflective glass)
Will work with many different glass types
Active area must be kept at least 2mm away
from metal (Active area is the whole surface
of the sensor)
No Issue with Metal
Can go out of calibration due to may
different environmental conditions.
No User calibration to perform for the life of
the product

43. Summary
• There are number of ways to do the same thing
• For a technology to succeed, it must be able to do ‘something’ the
others can’t (price, technical advantage, wider application range)
• You must know your pros and cons of each technology
• Must know the markets you attack
• Whatever makes your product easier to use…… DO IT
• Supply as much information as you can (drawings, data sheets, etc.).
Remember a happy customer never needs to talk to you!
• Customers know what they want (mostly), Listen
• You only get one chance!
• Quality/Reliability is important
• Keep in mind, no one (yet) has the touch Holy Grail But the Baanto’s
ShadowSense™ does bridge a wide variety of markets as a single touch
solution
• and also has multitouch capabilities….