Excellence in Electronics

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1 Excellence in Electronics Distribution Logistics Programming Development A Touch of Magic User Interface Design, Eindhoven, 6 februari Gerrit-Jan van Os / MSC-GE

2 MSC Atmel QTouch/QMatrix MSC Gleichmann Electronics Over 1500 employees R&D, 150 engineers in e.g. Stutensee, Neufahrn Production in e.g. Stutensee, Freiburg, China

3 Display Search indentifies 11 categories of touch screens 1/2

4 Display Search indentifies 11 categories of touch screens 2/2

5 Non-Capacitive Touch sensors

6 Why Projected Capacitive Touch? Resistive screen - Tends to collect dust and dirt - Added cost to make waterproof - Custom button shapes add cost Infrared screen - Weak mechanical performance - Membrane wears down and cracks - Sensitivity decreases Capacitive screens - Moisture resistant - Full freedom on button design - No performance degradation over time - Cost effective solution

7 Free Space Capacitance Model MSC Atmel QTouch/QMatrix

8 Free Space Capacitance Model With Handheld Devices MSC Atmel QTouch/QMatrix

9 MSC Atmel QTouch/QMatrix Theory of Capacitive Touch Finger adds capacitance to the touch sensor Change in C can be measured Multiple ways to do this All methods are capable of detecting a touch Selected technology will determine: Accuracy-over-temperature range, voltage and humidity Signal-Noise-Ratio Noise Immunity Power Consumption Moisture Tolerance Maximum overlay thickness QTouch and QMatrix are Atmel s methods for touch sensing

10 QMatrix - Basics MSC Atmel QTouch/QMatrix

11 MSC Atmel QTouch/QMatrix QMatrix - Basics X0 MCU VDD S2 S4 GND X Yk Cx X1 X2 X3 S1 GND Cs Y0 S3 GND Y Sampling capacitor Y1 Vsns Vcs Approximately linear Time 0.25V t -0.25V Time Terminal voltage Vyk

12 MSC Atmel QTouch/QMatrix QMatrix - What Happens During Touch? A finger close to electrode diverts charge from Cx, and so away from Cs E-field X Y EARTH Vcs Vcs No touch Touch Time Time Ct So each charge pulse now charges Cs by a smaller amount This means charge builds up in Cs less quickly So if each pulse deposits less charge, then Vcs rises slower, so reaches a smaller terminal voltage needs less time to discharge to GND so counter value gets less count change (delta) is proportional to Ct Delta

13 MSC Atmel QTouch/QMatrix Adjacent Key Suppression For small, tightly grouped touch keys, how do we resolve which key the user meant to press? Several keys can show detection at once Cross bleed can also tend to make several keys show strong signals Adjacent Key Suppression or AKS is the way to resolve this Think of AKS like a race between all the keys in detection trying to reach the winning line first

14 MSC Atmel QTouch/QMatrix ATMEL Technology Advantages AKS - Adjacent Key Suppression Spread Spectrum Modulation Superior EMC and EMI behavior Auto Calibration Adjusts for temperature, humidity, component fade on every key individually Covers slow and quick moving gradients Low power operation 1.8V 5.5V, multiple sleep modes Best field penetration & SNR Works in moisture environments Ease of system design

15 Classes of Touch Sensors Two main classes when referring to Indium-Tin-Oxide touch screens: - PolyEThyleen based - Glass based Each of above in two sub-classes: - Single layer ITO ( up to 7 screens) - Dual layer ITO New: PolyEThyleen dual layer with nano silver.

16 GE-Star Touch Sensors

17 Projective Capacitive Touch Sensor Cover glass OCA carrier Y-layer OCA X-layer carrier Display

18 Foil Integration Rules Avoid air gap between touch foil and glass!!!!!!!!! maximum distance of 0,1-0,2mm Make sure only the active sensor area covers the active display area. Other sensor structures like silver print and tail must be located outside to avoid noise problems Any cover foil on top of the touch sensor or front glas must be laminated to avoid false touch detections caused by varying air gaps

19 Mounting Possibilities Glue the border of touch sensor with a double side 3M tape with thickness lower than 0,2mm to the frontglass (this air gap is allowed)

20 Mounting Possibilities Glue the touch into a frame (metal frame is also possible). Glass cover is also located inside the frame TFT is behind the frame

21 GE-Star Features and Benefits GE- GE-

22 GE-Star Touch Controllers Three controller boards available: - For screens up to 9.1, from , and from 13.3 till 22 - Respectively supporting 224, 768, and 1386 nodes - USB or RS232 interface via On-board AT90USB162 - Drivers available for WinXP, Win7, Linux, Win CE 5.0/6.0 - Touch calibration and configuration directly over the driver for all OS

23 GE Star Touch Supporting Software

24 Supporting Software

25 Creating and supporting solutions with our partners:

26 MSC Atmel QTouch/QMatrix GE-Star Touch Sensors and Controllers Bedankt voor uw aandacht! Vragen? Gerrit-Jan van Os