Fundamentals of Touch Technologies

Fundamentals of Touch Technologies Geoff Walker Senior Touch Technologist Intel Corporation v1.1 Updated October, 2013 1 v1.3 File Download: www.walkermobile.com/Touch_Technologies_Tutorial_Latest_Version.pdf Agenda…1  Course structure Topic Allocation Introduction 6% Main Content 88% Capacitive – 1 32% Resistive – 2 9% Acoustic – 3 8% Optical – 4 20% Embedded – 5 13% Other – 6 2% Active Stylus – 7 6% Software – 8 10% Conclusions 6% TOTAL 100% 100%  6 fundamental touch technologies with ~20 types 2 Agenda…2  Admin  Introduction to Touch Technologies  Capacitive (1)  1A - Projected Capacitive (P-Cap)  ITO Replacement Materials  1B - Surface Capacitive  Resistive (2)  2A - Analog Resistive  2B - Analog Multi-Touch Resistive (AMR)  2C - Digital Multi-Touch Resistive  Acoustic (3)  3A - Surface Acoustic Wave (SAW)  3B - Acoustic Pulse Recognition (APR by Elo Touch Solutions)  3C - Dispersive Signal Technology (DST by 3M Touch Systems) 3 Agenda…3  Optical (4)  4A - Traditional Infrared  4B - Waveguide Infrared (DVT by RPO)  4C - Multi-Touch Infrared  4D - Camera-Based Optical  4E - Planar Scatter Detection (PSD by FlatFrog)  4F - Vision-Based  Embedded (5)  LCD Architecture Refresher & Terminology Review  Hybrid In-Cell Mutual Capacitive for IPS & Non-IPS LCDs  On-Cell P-Cap  In-Cell Light-Sensing  In-Cell “Pressed” Capacitive  In-Cell Voltage-Sensing  In-Cell Self-Capacitive  Embedded Touch Issues 4 Agenda…4  Other Touch Technologies (6)  Force-Sensing  Active-Stylus Technologies (7)  Electromagnetic Resonance (EMR) Stylus  P-Cap Stylus  Other Active Stylus Technologies  Software (8)  Multi-Touch  Operating-System Application-Development Support  Middleware 5 Agenda…5  Conclusions  Touch Technology vs. Application  Usability, Performance, and Integration Characteristics  Touch Technology Primary Advantages and Flaws  Predictions for the Future  Suggested Reading on Touch  Recommended Conferences and Trade Shows on Touch 6 Introduction Source: Gizmodo 7 (Michelangelo's "The Creation Of Adam“, in the Sistine Chapel, 1511) File Download: www.walkermobile.com/Touch_Technologies_Tutorial_Latest_Version.pdf Two Basic Categories of Touch  Opaque (non-transparent) touch  Dominated by the controller chip suppliers ● Atmel, Cypress, Synaptics, etc. ● One technology (projected [self] capacitive) ● Sensor is typically developed by the device OEM  Notebook touchpads are the highest-revenue application ● Synaptics, Alps and ELAN have the majority of the market ● Sensors are all two-layer projected capacitive  There is no further discussion of opaque touch in this course  Transparent touch on top of a display  Dominated by the touch module manufacturers (150+ worldwide)  6 fundamental technologies with ~20 types 8 Overall Touchscreen Market 2012-2017 Source: DisplaySearch Quarterly Touch-Panel Market Analysis Report (June 2013) 1.3 1.6 1.8 2.1 2.3 2.4 0.0 0.5 1.0 1.5 2.0 2.5 3.0 2012 2013 2014 2015 2016 2017 $24.2 $34.2 $39.1 $43.4 $46.0 $46.2 $0.0 $5.0 $10.0 $15.0 $20.0 $25.0 $30.0 $35.0 $40.0 $45.0 $50.0 $55.0 2012 2013 2014 2015 2016 2017 Units (Billions) Revenue ($Billions) 2012-2017 CAGR = 13.0% 2012-2017 CAGR = 13.8% Touch in 2007 was 308M units & $1.3B… 9 Touchscreen Market 2007-2017 by Technology (Units) % of Units Shipped Source: DisplaySearch Touch-Panel Market Analysis Reports 2008-2013 10 4% 13% 23% 41% 62% 63% 58% 59% 60% 61% 63% 93% 85% 75% 57% 28% 20% 16% 13% 11% 9% 8% 8% 9% 12% 15% 15% 14% 14% 6% 11% 10% 11% 12% 13% 3% 2% 1% 3% 2% 2% 3% 3% 3% 3% 3% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 2007A 2008A 2009A 2010A 2011A 2012A 2013F 2014F 2015F 2016F 2017F Other Technologies In-Cell (P-Cap) On-Cell (P-Cap) Resistive P-Cap [...]... reduction of light Change in image Presence of light Force The ideal method of sensing touch has yet to be invented! 15 Capacitive Touch Technologies  Projected Capacitive (P-Cap)  ITO-Replacement Materials  Surface Capacitive File Download: www.walkermobile.com /Touch_ Technologies_ Tutorial_Latest_Version.pdf 16 Projected Capacitive Source: Apple File Download: www.walkermobile.com /Touch_ Technologies_ Tutorial_Latest_Version.pdf... infrared (IR) Multi -touch infrared Camera-based Planar scatter detection (PSD) Vision-based = Emerging or Low-Volume Force sensing 12 A Simple Touch Isn’t Simple…1  Touch classification from the University of Toronto Example: iPhone/iPad Source: Daniel Wigdor 13 A Simple Touch Isn’t Simple…2  It’s far more complex than just “how many touches?” The Breadth vs Depth Problem ? Design software once for... 2A 2B 2C 3A 3B 3C 4A 4B 4C 4D 4E 5 6 Mobile (2” – 17”) Touch Technologies by Size & Application L E M L M E M E E E E E = Emerging Touch Technologies by Materials & Process Touch Technology Transparent Conductor (ITO) Continuous Patterned Acoustic Pulse Recognition (APR) Dispersive Signal Technology (DST) Analog resistive Analog & digital multi -touch resistive (AMR & DMR) = Mainstream No Edge Conductors... and columns of electrodes in two layers  Row & column electrodes are scanned in sequence 20 Projected Capacitive…4  The problem with self-capacitance Self Capacitance Mutual Capacitance No Ghost Points! Source: Touch International  Touches that are diagonally separated produce two maximums on each axis (real points & ghost points) ● Ghost points: False touches positionally related to real touches 21... Mutual-capacitance principle “Projected” electric field Touch No touch 22 Source: 3M Projected Capacitive…6  Mutual capacitance example (Apple iPhone) Source: Apple  Output is an array of capacitance values for each X-Y intersection Source: The Author 23 Projected Capacitive…7 Raw data including noise Gradient data Filtered data Touch region coordinates and gradient data Touch regions “10 fingers, 2 palms and 3... FF = Two sensor‐films, laminated to glass GF#  1 = Two ITO layers on one side of sensor‐film, laminated to glass (also called GF‐Single)  2 = One ITO layer on each side of sensor‐film,   laminated to glass (also called GFxy with metal mesh)  SITO  ITO on one side of substrate (single‐sided) DITO  ITO on both sides of substrate (double‐sided) F1T  F1 = Single‐sided sensor‐film on top of CF glass; T = Transmit (drive) electrodes on TFT glass ... complex operations) ● Bendable cover glass can affect touch performance ● Harder to shield touchscreen from LCD noise  Variation: G1F ● Sense electrodes on cover glass; drive electrodes on PET film 34 “One-Glass Solution” (OGS) Versus Embedded Touch 1 “One-Glass Solution” (OGS) versus Embedded Touch isn’t really about technology, it’s about The Touch- Panel Industry vs The LCD Industry 35 OGS Versus... Atmel 25 Projected Capacitive…9 Self-Capacitance Mutual Capacitance Older technology, but still used Newer technology Limited to 1 or 2 touches with ghosting Two or more unambiguous touches Lower immunity to LCD noise Higher immunity to LCD noise Lower touch accuracy Higher touch accuracy Sensor is usually a diamond pattern Allows more flexibility in pattern design Harder to maximize SNR Easier to maximize... Sensor structure abbreviations GF# is an  inconsistent  use of #     Symbol  Meaning (G)  Cover‐glass G  Cover‐glass, or sensor‐glass with ITO on one side, or plain glass for film lamination  GG  Cover‐glass + one sensor‐glass (without ITO location) GGG  Cover‐glass + two sheets of sensor‐glass (rare) G#  # = Number of ITO layers on one side of sensor‐glass       (G2 = “One Glass Solution” = OGS = SOC = SOL, etc.) ... touches?” The Breadth vs Depth Problem ? Design software once for common capabilities Re-design software for each platform’s capabilities (wide breadth, limited functionality) (narrow breadth, deep functionality) 14 Touch Is An Indirect Measurement  This is one reason why there are so many technologies Touch Technology Projected capacitive, Embedded (capacitive) Surface capacitive Resistive (all forms) . www.walkermobile.com /Touch_ Technologies_ Tutorial_ Latest_ Version. pdf Projected Capacitive Source: Apple 17 File Download: www.walkermobile.com /Touch_ Technologies_ Tutorial_ Latest_ Version. pdf Projected. Fundamentals of Touch Technologies Geoff Walker Senior Touch Technologist Intel Corporation v1.1 Updated October, 2013 1 v1.3 File Download: www.walkermobile.com /Touch_ Technologies_ Tutorial_ Latest_ Version. pdf Agenda…1 . Chapel, 1511) File Download: www.walkermobile.com /Touch_ Technologies_ Tutorial_ Latest_ Version. pdf Two Basic Categories of Touch  Opaque (non-transparent) touch  Dominated by the controller chip suppliers ●