Fundamentals of Touch Technologies

Two Basic Categories of Touch «* Opaque non-transparent touch + Dominated by the controller chip suppliers e Atmel, Cypress, Synaptics, etc.. e One technology projected [self] capacit

Fundamentals of

Touch Technologies

Geoff Walker Senior Touch Technologist

+ 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)

» 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" Capacttive + In-Cell ⁄oltage-Sensing

+ In-Cell Self-Capacitive + Embedded Touch Issues

«* Software (8)

+ Multi- Touch + Operating-System Application-Development Support

+ Middleware

DISPLAY WEEK 2013

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

(Michelangelo's "The Creation Of Adam“, in the Sistine Chapel, 1511)

Two Basic Categories of Touch

«* Opaque (non-transparent) touch

+ Dominated by the controller chip suppliers

e Atmel, Cypress, Synaptics, etc

e One technology (projected [self] capacitive)

e Sensor is typically developed by the device OEM

+ Notebook touchpads are the highest-revenue application

e Synaptics, Alps and ELAN have the majority of the market

e 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

Overall Touchscreen Market

2012-2017

Units (Billions) Revenue ($Billions)

$46.0 $46.2

Source: DisplaySearch Quarterly Touch-Panel Market Analysis Report (June 2013)

Touch in 2007 was 308M units & $1.3B

DISPLAY WEEK 2013

4B | Multi-Touch Infrared 4C | Camera-Based Optical 4D | Planar Scatter Detection (PSD) 4E | Vision-Based (In-Cell Optical)

2 Embedded (In-Cell/On-Cell Capacitive) Force Sensing

| L |= Low-volume

| M |= Mainstream

Continuous Patterned Edge Conductors No Edge

A Simple Touch Isn’t Simple 1

“* Touch classification from the University of Toronto

Example: _ Contact Partial

Single-User Gestural — Stylus Only

Continuous

Sensed styl L lo ved Sensed

Objects Differentiated Information Contact a ane!

A Simple Touch Isn't Simple 2

Touch Is An Indirect Measurement

Acoustic Pulse Recognition &

Dispersive Signal Technology

Capacitive Touch Technologies

“* Projected Capacitive (P-Cap) s*» [TO-Replacement Materials

“* Surface Capacitive

Projected Capacitive 1

s» iPhone, iPad and other products using projected

capacitive (p-cap) have set the standard for touch

in SEVERAL BILLION consumers’ minds

+ Multiple simultaneous touches + Extremely light touch

+ Flush surface (zero-bezel)

+ Excellent optical performance + Reliable and durable

+ Fully integrated into the user

Source: TabletPC2.com

+ Each pad is scanned + Row & column electrodes are

Projected Capacitive 4

«* The problem with self-capacitance

self Capacitance Mutual Capacitance

Intersection Source: The Author Touch sensor Output to

host computer

Source: Apple Patent Application #2006/0097991

DISPLAY WEEK 2013

G Cover-glass, or sensor-glass with ITO on one side, or

plain glass for film lamination

GGG _| Cover-glass + two sheets of sensor-glass (rare)

a GH # = Number of ITO layers on one side of sensor-glass

F = Sensor-film with ITO on one side, laminated to glass

FF = Two sensor-films, laminated to glass

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) ITO on one side of substrate (single-sided)

ITO on both sides of substrate (double-sided) F1 = Single-sided sensor-film on top of CF glass;

T = Transmit (drive) electrodes on TFT glass (LG Display’s hybrid in-cell/on-cell)

GF# isan inconsistent

use of #

Projected Capacitive 11

«* Summary of all p-cap constructions

+ Embedded sensor

e On-cell = Both electrodes on top of color filter glass (or OLED glass)

>» Example = Samsung $1/2/3, Toshiba Excite 7.7

e In-Cell = Both electrodes on TFT array

>» Example = iPhone-5 & iPod Touch-5

e Hybrid In-Cell/On-Cell = Drive electrodes in TFT array;

sense electrodes on top of CF glass

>» Example = HTC EVO Design, Sony Xperia S

+ Glass-only sensor

e OGS or G2 = cover-qlass with ITO on one side with bridges

>» Example = Google Nexus 4 & 7, many others

e (G)G-SITO or GG = one ITO-glass with ITO on one side with bridges

>» Example = Kindle Fire & HD, HTC Sensation, many others

e (G)G-DITO or GG = one ITO-glass with ITO on each side (Apple patent)

>» Example = iPhone & iPad 1-4

e (G)GG or GGG = two sheets of ITO-glass with ITO on one side of each

Top Polarizer Color Filter Glass Color Filter

Liquid Crystal TFTs

TFT Array Glass

Source: The Author

Projected Capacitive 13

«* P-cap constructions (continued)

+ Film-only sensor

e (G)FF or GFF = two single-sided ITO-films laminated on cover-glass

>» Example = Samsung Galaxy Tab 7/8.9/10, HTC One X

e (G)F-DITO or GF2 = one double-sided |TO-film laminated on cover-glass

>» Example = Apple iPad mini

e (G)F1 or GF1 = one film with ITO on one side with bridges, or

one film with two insulated layers of ITO on one side, laminated on cover-glass

>» Example = 2

+ Glass and film sensor

e (G)1F or G1F = glass with ITO on one side and

one single-sided ITO film laminated to it

>» Example = Microsoft Surface RT

Liquid Crystal

TFTs TFT Array Glass

Source: The Author

+ Thickness & weight + Existing equipment and/or method experience

‹» Terminology note

+ “Lamination” = Adhering film to glass, or film to film

+ “Bonding” = Adhering touchscreen to display

e Direct bonding = No air-gap

e Air-bonding = Air-gap (gasket around periphery)

Mechanical Strengthening None Chemical, heat,

ion-exchange

Projected Capacitive 17

s» One-Glass Solution (OGS)

J (í

+ Also called “touch on lens", “sensor on cover’,

“direct patterned window” and many other names

e Yields are lower (more complex operations)

e Bendable cover glass can affect touch performance

e Harder to shield touchscreen from LCD noise + Variation: G1F

e Sense electrodes on cover glass; drive electrodes on PET film

“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

OGS Versus Embedded 2

The end-user can’t tell the

difference (except for the off-screen buttons)

OGS versus Embedded 3

«* What the device OEM buys

+ OGS

e Touch-panel/cover-glass from TP supplier

e Standard LCD from LCD supplier

e Nothing from CG supplier

+ Embedded

e Different LCD with embedded touch from LCD supplier

e Cover glass from CG supplier This is a robust

e NOTHING from TP supplier $24B business

(2012) that’s not going to give up without a fight

OGS versus Embedded 4

«* What the device OEM would like to buy

+ Laminated LCD/touch-panel/cover-glass module

s$s Problem

+ LCD suppliers don’t want to get into the cover-glass business — each device's cover-glass is unique

“* Solution

+ Touch-panel suppliers are very willing to get into the

cover-glass business (vertical integration)

e For example, TPK spent $250M on cover-glass equipment in 2011 + Touch-panel suppliers can get LCDs on consignment or buy/sell and build the complete module

OGS versus Embedded 5

«* The influence of the controller suppliers

+ It's fundamentally the same controller for OGS & embedded

e Simple case: Touch controller & display driver communicate (linked)

» What's in today’s smartphones with embedded touch

e Optimized case: Touch controller is integrated with display driver

» It's a specialized, resolution-specific ASIC

+ The controller supplier can swing the pendulum

e Synaptics wants to work very closely with LCD suppliers

to create optimum embedded designs

e Atmel is considering the embedded opportunity, but it’s far from a defined strategy for them

e Cypress?

e The 20+ other controller suppliers?

+ Do the controller suppliers want to trade 30 module customers

for 5 LCD customers?

OGS versus Embedded 6

«* The problem of LCD product-management

+ An LCD with embedded touch is a different product

e In many cases the LCD supplier may have two versions of

a given LCD — one with touch and one without

e The touch version will cost more, so it can’t be the only version

Miscellaneous P-Cap

Construction Issues

«- “Sheet” method vs “Piece” method

+ Sheet: Harden first, then cut (requires 2"? strengthening)

e Example: Wintek (cumulative yield = 75% typical) + Piece: Cut first, then harden

e Example: TPK (cumulative yield = 60% typical)

“* Bonding to LCD

+ OCA (film) vs OCR (liquid)

e Trend is towards OCR

“* Cover-glass material

+ Industry would like to switch from glass to plastic (e.g., PMMA)

» Apple s “flooded-X” patent for self-shielding

+ Currently in lawsuit; the author believes the patent will be

invalidated due to prior art

¢¢ Controller innovation areas

+ Performance, power, cost, stylus & palm- — rejection, hover, gloves, water-resistance, | pressure, gestures, proximity, haptics - + When will controller commoditization Source: Synaptics

with Synaptics’ p-cap touch-

screen; launched 3 months before the iPhone!

Projected Capacitive 21

“* Options (ITO-based )

+ Top-surface treatment (AR, AG, AF, AC, AB )

+ Degree of indexing matching on ITO (invisibility) + Stackup variations, as already described

+ Number of electrodes per inch (dpi/resolution)

“* Size range

+ 2° to 100°+

e [TO up to 32” (3M’s 46’ is a special case)

e 10-um wire electrodes up to 100°+

Projected Capacitive 22

“* Advantages

+ Unlimited multi-touch + Extremely light touch (zero force) + Enables “zero-bezel” industrial design + High optical quality (with index-matched ITO)

+ Very durable (protected sensor)

+ Unaffected by debris or contamination

+ Works with curved substrates (on PET)

Integrating a P-Cap Touchscreen

Into a Mobile Device

«* After the mechanical & industrial design are done,

it’s really all about just one thing: “Tuning”

+ Every new product must have the p-cap touch-screen

controller “tuned” to account for all the variables in the configuration

e Basic configuration (e.g., OGS vs embedded)

e Air-gap or bonded etc

+ All controller manufacturers either supply tools (e.g., Synaptics’

“Design Studio 4°) or they do it themselves for their OEM customers

e Tablets, Ultrabooks, AiOs

e Almost any consumer device

Projected Capacitive 24

«* In the USA, this is probably the fastest-growing

commercial p-cap application

Source: Verifone

Projected Capacitive 25

«* Adoption of P-Cap In Commercial Markets (Forecast)

+ Healthcare — Rapid, within FDA-cycle constraints

e Buying for the future with a very long product life

e Zero-bezel, multi-touch, light touch are all important

+ Gaming — Rapid, within gaming regulation constraints

e Casinos want to attract the Millennium Generation

e Multi-touch is very important; zero-bezel is less so

+ Point of Information — Moderate

e Software-driven; zoom gesture could be the key

+ Industrial — Slow

e Multi-touch may be important; zero-bezel & light touch are less so

+ Point of Sales — Very slow

e Zero-bezel is the only driver; “flat-edge resistive” is good enough

Projected Capacitive 27

“* Market trends

+ P-cap has become a de facto standard (it’s won the war!)

+ Growth is starting to slow down

+ Capacity expansion continues but at a slower pace

+ Top three controller suppliers account for ~/0% of revenue + Top five module suppliers account for ~50% of revenue

+ Intel announced that all Haswell (2013) Ultrabooks must have touch + Market research firms are expecting more notebook penetration

+ Commercial applications are beginning to transition to p-cap

+ Afew small-order suppliers are appearing, but it’s still hard to buy + The technology name has changed to just “capacitive”

Large-Format P-Cap 1

¢*¢ One more sensor variation: 10-micron wires

between two sheets of PET or glass

+ Commonly used for large-format touchscreens

+ Two main suppliers: Visual Planet & Zytronic, both in the UK

9 floor-to-ceiling Visual Planet touchscreens in the University of Oregon Alumni

Large-Format P-Cap 2

«* 3M has managed to get ITO electrodes to work

in a 46-inch display (larger than any other with ITO)

+ They wont disclose their secret sauce

Large-Format P-Cap 3

«* Jeff Han from Perceptive Pixel (acquired by Microsoft

in mid-2012) showed an 82” at CES 2012 (with active

stylus) and a 72” at Digital Signage Expo (DSE) 2012

+ Metal electrodes (not ITO) — although Jeff wouldn't talk about the electrode material or who is manufacturing the touchscreens

Large-Format P-Cap 4

** Both the 72” & 82” look much better than the

traditional Zytronic zig-zag 10-micron wire pattern