Transcript CleaTek II Capacitive Technical Training with Marks

3M Touch Systems
ClearTek II Touch Screen
© 3M 2007. All Rights Reserved
3M CONFIDENTIAL
3M Touch Systems
ClearTek II Touch Screens - Construction
Proprietary ScratchResistant Top Coat
ClearTek Hard Coat with Anti-Glare
Electrode Pattern
Conductive Coating
Glass
• All glass touch screen with transparent,
thin-film conductive coating applied to surface
• A narrow electrode pattern is printed along the
edge of the conductive layer
• Transparent glass hard coat with anti-glare
properties is fused over the conductive coating
• Proprietary scratch-resistant top coat added
• Tail design with solder-less connection and
taped strain relief
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© 3M 2007. All Rights Reserved
3M CONFIDENTIAL
3M Touch Systems
ClearTek II - Tail Design
•Tail has 4 corner wires in a copper layer
• It also has a conductive shield – top & bottom
• This is connected to pin 3 of the controller
• This shield protects the 4 corners from EMI interference
• Insulation layer protecting the shield layers
• The insulating layers protect the shield from shorting out
• During integration, ensure sharp metal edges do not contact
or rub against the outside insulating layers of the tail.
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© 3M 2007. All Rights Reserved
3M CONFIDENTIAL
3M Touch Systems
Standard Touch Screen Configurations
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3M CONFIDENTIAL
3M Touch Systems
Serial Number Label Information
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Example of a Serial Number Label
 Example of 14 digit serial number – NA170611300126
 AAAA – NA17 – Machine ID #
 YY – 06 – Year Manufactured 2006
 MM – 11 – Month Manufacture 11 or November
 DD – 30 – Day Manufactured 30
 SSSS – 0126 – Sequence # for the day
 Manufacturing date – Nov 30, 2006; 126 touch screen of the day
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© 3M 2007. All Rights Reserved
3M CONFIDENTIAL
3M Touch Systems
Scratch Resistance – Mohs Scale
The Mohs scale of mineral hardness characterizes the scratch resistance of various minerals
through the ability of a harder material to scratch a softer material. It was created in 1812 by the
German mineralogist Friedrich Mohs and is one of several definitions of hardness in materials
science.
Hardness
Mineral
Absolute
Hardness
10
Diamond
1500
9
Corundum
400
8
Topaz, Hardened Steel
200
7
Quartz, Garnet, 3M Capacitive Touchscreen
100
6
Orthoclase Feldspar, Glass, Iron Pyrite
72
5
Apatite, Knife Blade
48
4
Fluorite, Platinum, Iron
21
3
Calcite, Copper
9
2
Gypsum, Finger Nail, Gold, Silver
2
1
Talc
1
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© 3M 2007. All Rights Reserved
3M CONFIDENTIAL
3M Touch Systems
How Does Capacitive Work
 Voltage source (V) applied to surface
 Amplifiers (A1 – A4) measure current &
gain from the corners. Gain is in
phase for all 4 corners correct ?
 When a touch occurs a new circuit is
introduced.
 Current is drawn from the touch screen,
through the person, to ground.
 The Ratios of the current in each
corner is used to calculate the position
of the touch.
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© 3M 2007. All Rights Reserved
3M CONFIDENTIAL
3M Touch Systems
Linearization
 Non-linear areas of the touch screen

Raw glass

Conductive coating

Resistance of the border pattern
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3M Touch Systems
Linearization Process
 Linearization corrects non-linearity of the
glass, conductive coating process,
electrode pattern process
Measured Data X&Y
 Linearization compares measured data
points to ideal data points.
Ideal Data X&Y
Before linearization
 Comparison generates correction
coefficients for X & Y position.
 Correction coefficients are stored either in
the controller or with the touch screen.
 Each touch screen has unique correction
coefficients, Novram or mated controllers
should not be separated from the touch
screen it was paired with.
After linearization
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© 3M 2007. All Rights Reserved
3M CONFIDENTIAL