`Projected-Capacitive
`Touch Technology
`
`Geoff Walker
`Senior Touch Technologist
`
`Intel Corporation
`
`|
`
`
`Must use exact
`
`capitalization!
`
`
`(intel)
`SID DISPLAY WEEK ‘14 12
`
`File Download: www.walkermobile.com/Touch_Technologies_Tutorial_Latest_Version.pdf
`
`June 1, 2014
`
`SAMSUNG EXHIBIT 1011 (Part 1 of 3)
`
`
`
`Agenda
`
`*¢ Introduction
`** Basic Principles
`** Controllers
`
`** Sensors
`** |[TO-Replacement Materials
`
`«+ Large-Format
`“* Stylus
`“+ Software
`
`** Conclusions
`** Appendix A: Historical Embedded Touch
`SID DISPLAY WEEK ‘14
`
`
`
`Introduction
`
`“+ P-Cap History
`** P-Cap Penetration
`** P-Cap by Application
`** Touch User-Experience
`
`File Download: www.walkermobile.com/Touch_Technologies_Tutorial_Latest_Version.pdf
`
`SID DISPLAY WEEK ‘14
`
`3
`
`Tee
`
`
`
`
`Must use exact
`
`capitalization!
`
`
`
`
`
`P-Cap History
`
`UK Royal Radar
`Establishment
`E.A. Johnson
`CERN(Bent Stumpe)
`
`Dynapro Thin Films
`(acquired by 3M Touch
`Systems in 2000
`Zytronic(first license from
`Ronald Binstead, an
`inventor in the UK)
`
`First published application of transparent
`touchscreen (mutual-capacitance p-cap on
`CRTair-traffic control terminals
`Second published application of mutual-
`capacitance p-cap(in the control room of
`the CERNproton synchrotron)
`First commercialization of mutual-
`
`1965
`
`1977
`
`1995
`
`1998
`
`2012
`
`self-capacitive p-cap;
`first commercialization of large-format
`mutual-capacitive p-cap
`Visual Planet (second Second commercialization of large-format|2003
`
`license from Ronald
`self-capacitive p-cap
`Binstead
`Apple
`
`(the iPhone
`
`First use of mutual-capacitive p-cap in a
`consumerelectronics product
`
`2007
`
`SID DISPLAY WEEK ‘14
`
`7
`
`Te
`
`
`
`P-Cap Penetration
`
`
`
`% of Units Shipped
`2.8% 24% 1.3%
`
`100%
`
`2.5% 1.2% 0.6% 0.3%
`
`0.3% 0.2% 0.2% 0.2%
`
`@ On-Cell (P-Cap) @ Resistive
`
`90%
`
`80% --
`
`70%
`
`60%
`
`50% --te4—
`
`40%
`
`30%
`
`20%
`
`10%
`
`0% maa
`
`Embedded
`= P-Cap
`
`®™ Other Technologies
`
`@ In-Cell (P-Cap)
`
`m P-Cap
`
`2007A 2008A 2009A 2010A 2011A 2012A 2013A 2014F 2015F 2016F 2017F 2018F
`
`SID DISPLAY WEEK ‘14
`
`Source: DisplaySearch Touch-Panel Market Analysis Reports 2008-2014
`
`
`
`P-Cap Forecast by Application...1
`(Consumer)
`
`Million Units
`120
`
`20
`
`
`
`_
`
`60
`
`™ PDA
`™ Desktop Monitor
`
`™ Video Camera
`
`© All-in-one PC
`
`™ Portable Game
`
`§ Still Camera
`
`™ EPD eReader
`
`— li Media Player
`
`™ Smart Watch
`
`®@ Navigation Device
`
`™ Notebook PC
`
`2012
`
`2013
`
`2014
`
`2015
`
`2016
`
`2017
`
`2018
`
`EE2018: Phones = 1.8 Billion Units; Tablets = 447 Million Units
`SID DISPLAY WEEK ‘14
`6
`
`Source: DisplaySearch Touch-Panel Market Analysis Report 1Q-2014
`
`Koy
`
`
`
`P-Cap Forecast by Application...2
`(Commercial)
`
`Million Units
`8.0
`
`™ Education/Training
`
`© Point of Interest
`
`© Ticketing/Check-in
`
`™ Casino Game
`
`® Medical Equipment
`
`& ATM Machine
`
`® Office Equipment
`@ Retail and POS/ECR
`
`2012
`
`2013
`
`2014
`
`2015
`
`2016
`
`2017
`
`2018
`
`2018: Automobile Monitor = 42 Million Units
`
`Source: DisplaySearch Touch-Panel Market Analysis Report 1Q-2014
`
`SID DISPLAY WEEK ‘14
`
`7
`
`Koy
`
`
`
`
`
`
`
`® Factory Equipment
`
`
`
`P-Cap Defines the Standard
`for Touch User-Experience
`
`«* Smartphones and tablets have set the standard
`for touch in SEVERAL BILLION consumers’ minds
`
`+ Multiple simultaneous touches
`(robust multi-touch)
`+ Extremely light touch (zero force)
`+ Flush surface (“zero-bezel”
`or “edge-to-edge’)
`
`+ Excellent optical performance
`+ Very smooth & fast scrolling
`+ Reliable and durable
`
`+ An integral part of the
`device user experience
`
`SID DISPLAY WEEK ‘14
`
`#E
`
`esd ’Boasxiet‘ect’
`
`vneS a aX
`;
`;
`
`
`
`
`
`Basic Principles
`
`“+ Self Capacitive
`** Mutual Capacitive
`** Mutual Capacitive Electrode Patterns
`
`SID DISPLAY WEEK ‘14
`
`
`
`Self-Capacitance
`
`** Capacitance of a single electrode to ground
`+ Human body capacitance increases the capacitance
`of the electrode to ground
`+ In a self-capacitance sensor, each electrode is measured
`individually
`
`No Touch ¢
`
`i
`
`
`
`Source: The author
`
`SID DISPLAY WEEK ‘14
`
`1
`
`
`
`The Problem with Self-Capacitance
`
`** Touchesthat are diagonally separated produce
`two maximumson eachaxis (real points & ghost points)
`+ Ghost points = False touchespositionally related to real touches
`
`Self Capacitance
`
`Mutual Capacitance
`
`Ghost Points
`
`Source: Atmel
`
`SID DISPLAY WEEK ‘14
`
`1
`
`Tee
`
`
`
`Self-Capacitance and
`Pinch/Zoom Gestures
`
`«* Use the direction of movement of the points rather
`than the ambiguouslocations
`
`
`
`X1
`
`X2
`
`X3
`
`X4
`
`Source: The author
`
`
`
`SID DISPLAY WEEK ‘14
`
`
`
`Self-Capacitance Electrode Variations
`
`A g —
`,
`kik ewi
`—jpmilo
`| eeea |
`ell
`eel
`Manel
`nc '
`St
`Mell
`lite
`[no —:|
`Leal
`Mall
`iene]
`ne |
`Saale
`Ucenaill
`liens)
`
` Sa yh
`
`a—
`
`fpfe
`
`20 measurements
`
`Source: 3M
`
`20 measurements
`
`+ Multiple separate pads
`in a single layer
`+ Each pad is scanned
`individually
`
`+ Rowsand columnsof electrodes
`in two layers
`+ Row & columnelectrodes are
`scanned in sequence
`
`SID DISPLAY WEEK ‘14
`
`13
`
`TD
`
`
`
`Self-Capacitance
`Advantages & Disadvantages
`
`Limited to 1 or 2 touches with ghosting
`Simpler, lower-cost sensor
`Lower immunity to LCD noise
`Can be a single layer
`Long-distance field projection|Lower touch accuracy
`Can be used with active guard|Harder to maximize SNR
`
`[Fastmeasurement|
`
`«* Whereit’s used
`
`+ Lower-end smartphones and feature-phones with touch
`e Becoming much less common dueto single-layer p-cap
`+ In combination with mutual capacitance to increase capability
`
`
`
`SID DISPLAY WEEK ‘14
`
`
`
`Self-Capacitance for Hover
`
`«* Self-capacitance is used to produce “hover”
`behavior in some smartphones(in addition to
`mutual-capacitance for contact-touch location)
`+ Also used for automatically detecting glove vs. fingernail vs. skin,
`
`and for dealing with water on the screen Source: Panasonic
`
`SID DISPLAY WEEK ‘14
`
`
`
`Multi-Touch Self-Capacitance
`Using Active Guard Concept...1
`
`«+ Guarding is a well-known techniquefor reducing the
`effects of electrical current leakage
`
` Leakage capacitance < 10 aF
` ‘\I
`
`
`Source: Fogale
`
`
`
`C06
`
`
`
`IIII
`
`I|
`
`SID DISPLAY WEEK ‘14
`
`
`
`Multi-Touch Self-Capacitance
`Using Active Guard Concept...2
`
`¢* Another contender: ZRRo
`
`for smartphones
`
`
`
`
`_ 3D multi-touch
`_
`for smartphones
`ae i and tablets
`
`3D single-touch
`
`Koy
`1
`SID DISPLAY WEEK ‘14
`
`Source: ZRRo
`
`
`
`Mutual Capacitance
`
`«+ Capacitance between two electrodes
`+ Human body capacitance “steals charge” which decreases
`the capacitance betweenthe electrodes
`+ In a mutual-capacitance sensor, each electrode intersection
`is measuredindividually
`
`Glass
`
`Electrode
`
`Sense
`Electrode
`
`Electrode
`
`Sense
`Electrode
`
`
`
`SID DISPLAY WEEK ‘14
`
`Source: The author
`
`
`
`Mutual Capacitance
`Electrode Patterns...1
`
`** Rows and columnsof
`electrodesin two layers
`
`TrittSsTTTa1 Source: 3M
`eeaa
`
`¢* In the real world...
`
`+ “Bar and stripe”, also called
`“Manhattan”or “Flooded-xX”
`(LCD noise self-shielding)
`
`11 x 9 = 99 measurements
`
`| | | Lill | —
`
`4x
`
`10 = 40 measurements
`
`
`
`SID DISPLAY WEEK ‘14
`
`
`
`Mutual Capacitance
`Electrode Patterns...2
`
`«* Interlocking diamond pattern
`with ITO in “one layer” with bridges
`
`4.5mm typical
`PECELECCCCECCCs
`0000800888888 8888
`POTCOeeeeeeee eeee
`reece
`all
`10000000000 OX,
`Wire or ITO
`PRNENbe)
`LO eeeeteee eee. a
`OOOO eeeeeeeee eee
`Le eeeeeeeeTete’
`lalataleloteteteloletetetetetetes
`
`Source: 3M
`
`
`
`SID DISPLAY WEEK ‘14
`
`Source: The author
`
`
`
`More On Mutual Capacitance...1
`
`«+ BTW, there isn’t just one mutual capacitance...
`
`
`
`
`
`SID DISPLAY WEEK ‘14
`
`Source: Cypress
`
`
`
`More On Mutual Capacitance...2
`
`Equivalent
`
`Sensing Signal
`
`«* And there are more capacitors thanjust the C,,’s... Finger
`
`SID DISPLAY WEEK ‘14
`
`Py
`
`Source: ELAN, modified by the author
`
`
`
`More On Mutual Capacitance...3
`
`
`
`2 or more unambiguous touches|More complex, higher-cost controller
`Higher immunity to LCD noise
`2 layers (or 1 with bridges) for >3 pts
`Higher touch accuracy
`Moreflexibility in pattern design Pe
`Easier to maximize SNR po
`
`«“* Where it’s used
`
`+ Mid & high-end smartphones,tablets,
`Ultrabooks, AiOs, commercial products
`e Standaloneself-capacitive is becoming increasingly rare
`in consumerelectronics (except for buttons)
`+ With “true single-layer” sensors in low-end smartphones
`
`SID DISPLAY WEEK ‘14
`
`rx)
`
`Toy
`
`
`
`Mutual Capacitance
`Electrode Patterns...3
`
`«* Bars & stripes require bridgestoo...
`
`
`
`
`
`Mutual Capacitance
`Electrode Patterns...4
`
`** And so doesthis unusual diamond pattern...
`
`e Blank (no ITO)
`
`e Bridges
`+ 120 & 230
`
`+ 102, 106, 108, 210
`e Drive (X) electrodes
`+ 114 & 202
`
`e Sense(Y) electrodes
`+ 110
`
`e Dummy(floating) ITO
`+ 200 & 206
`
`e Optional dummy ITO
`+212
`
`Source: STMicro
`
`
`
`SID DISPLAY WEEK ‘14
`
`
`
`Mutual Capacitance
`Electrode Patterns...5
`
`«+ Claimed advantagesofthis particular
`pattern overtraditional interlocking diamond
`+ Reduction in sense electrode area reduces LCD noise pickup
`+ “Finger projections” (0.1 — 0.2 mm) increase the perimeterof
`interaction between drive and senseelectrodes, which
`increases sensitivity
`+ Linearity is improved due to more uniform coupling across channels
`+ Floating separators aid in increasingthefringing fields, which
`increases sensitivity
`
`SID DISPLAY WEEK ‘14
`
`rr
`
`am),
`
`
`
`Mutual Capacitance
`Electrode Patterns...6
`
`** Holy Grail: True single-layer mutual Capacitance sensor
`
`touches
`
`“* “Caterpillar” pattern
`+ Everybody’s single-
`layer patterns are
`proprietary
`+ Requiresfine
`patterning, low sheet
`resistance & low
`visibility
`+ Benefits: Narrow
`borders, thin stack-
`ups, lower cost, can
`reliably handle 2-3
`
`Source: Synaptics
`
`SID DISPLAY WEEK ‘14
`
`ra
`
`Gee
`
`
`
`Mutual Capacitance
`Electrode Patterns...7
`
`** ELAN’s caterpillar pattern
`x1
`x2
`
`x3
`
`x4
`
`
`
` SID DISPLAY WEEK ‘14
`
`Source: ELAN
`
`
`
`Mutual Capacitance
`Electrode Patterns...8
`
`«* An alternative true single-layer pattern from ELAN
`+ This is a very small portion
`
`of a muchlarger sensor
`
`
`
`SID DISPLAY WEEK ‘14
`
`
`
`Controllers
`
`** Architecture
`** Touch Image Processing
`*“* Key Characteristics
`** Signal-to-Noise Ratio
`** Noise Management
`¢,~°¢
`Innovation Areas
`Suppliers
`
`?%
`
`SID DISPLAY WEEK ‘14
`
`
`
`Mutual Capacitance
`Touch System Architecture
`
`Sense
`Electrodes
`
`Analog Front-
`End (AFE)
`
`Analog-
`to-Digital
`Converter
`(ADC)
`
`Digital
`Signal
`Processor
`(DSP)
`
`Interface Capacitive Nodes
`
`Electrodes
`
`Sensor
`Driver
`
`Host
`
`
`
`Touch Sensor Touch Controller—_Source: The author
`
`+ Making X*Y measurementsis OK,butit’s better
`to measure the columns simultaneously
`+ Controllers can be ganged (operate in a
`master-slave relationship) for larger screens
`
`
`
`SID DISPLAY WEEK ‘14
`
`
`
`Touch Image Processing
`
`Raw data including noise
`
`Filtered data
`
`Gradient data
` Touch region coordinates
`
`
`“10 TINGELS,
`2 palms
`and
`
`3 others”
`
`and gradient data
`|F88zBBm
`=
`
`-
`8=93.00 p=133.97
`x=707.07.04, y=331.323236
`
`a=35.00 Pl 374
`¥=290, 16, y=570, 158990
`
`Source: Apple Patent Application #2006/0097991
`
`SID DISPLAY WEEK ‘14
`
`
`
`Key Controller Characteristics...1
`
`** Node count (x channels + y channels)
`+ Giventypical electrode spacing of 4.5 to 5 mm, this determines
`how large a touchscreenthe controller can support (w/o ganging)
`** Scan rate
`
`+ Frames per second (fps) — faster reduces latency for a better UX
`+ Windowslogo requires 100 fps; Android is unspecified
`«+ Signal-to-noise ratio (SNR)
`+ More info on upcomingslides
`«+ Operating voltage & current
`+ OEMscontinue to request lower-power touchscreen systems
`+ Win8 “Connected Standby”is a significant influence
`«* Internal core (micro/DSP)
`+ Varies from small 8-bit micro to ARM-7 or higher
`SID DISPLAY WEEK ‘14
`cK)
`
`Gee
`
`
`
`Key Controller Characteristics...2
`
`¢“* Number of simultaneous touches
`
`+ Windows Logo requires 5 (except AiO = 2); Android is unspecified
`+ Market trend is 10 for tablets and notebooks
`
`«+ Support for unintended touches
`+ “Palm rejection”, “grip suppression”, etc.
`+ Rarely specified, but critically important
`+ For a 22” screen, even 50 touchesisn’t too manyin this regard
`«+ Amount of “tuning” required
`+ Never specified — more info on upcomingslide
`
`SID DISPLAY WEEK ‘14
`
`34
`
`am),
`
`
`
`Signal-to-Noise Ratio (SNR)...1
`
`«“* SNR = Industry-standard performance metric
`for p-cap touchscreen systems
`+ However, no standard methodologies exist for measuring,
`calculating, and reporting SNR
`+ The two components (signal & noise) depend heavily on
`the device undertest
`
`** Noise from displays (LCDs & OLEDs) and from
`USB chargersis spiky — it doesn’t have a normal
`(Gaussian) distribution — and spikescreatejitter
`+ Yet marketers typically specify SNR in the absence of noise,
`using the RMS noise (standard deviation) of analog-to-digital
`convertors (ADCs)
`+ With Gaussian noise, you can multiply the RMS noise by6 to
`calculate the peak-to-peak noise with 99.7% confidence
`
`SID DISPLAY WEEK ‘14
`
`
`
`Signal-to-Noise Ratio (SNR)...2
`
`«+ Typical system (raw ADC data, no digital filters applied)
`
`(modified by the author)
`
`Source: Cypress
`
`
`
`
`
`Quantizedoutput(LSBs)
`
`
`
`
`
`Signal-to-Noise Ratio (SNR)...3
`
`«* SNR of system in previousslide
`
`+ Cringer = Mean (Finger) - Mean (NoFinger)
`+ Cringer = 1850 - 813 = 1037
`
`+ Cys (Standard Deviation) = 20.6 counts
`+ Cys (Peak-to-Peak) = Max (NoFinger) - Min (NoFinger) +1
`+ Cys = 900 - 746 +1 = 155 counts
`
`+ SNR (Peak-to-Peak) = 1037/155 = 6.7
`+ SNR (Standard Deviation) = 1037/20.6 = 49.9
`+ Highest SNR currently reported by marketer = 70 dB (3,162*)
`
`* Signal amplituderatio in dB = 2010949 (A; / Ao)
`
`SID DISPLAY WEEK ‘14
`
`cy
`
`
`
`Noise Management...1
`
`«+ Charger noise is common-mode
`+ Asmartphone on a desk(not handheld)isn’t grounded, so the
`entire phone movesrelative to earth groundasit follows the noise
`+ A touching finger provides an alternative path to ground, which
`is equivalent to injecting the noise at the finger location
`+ The noise signal can be 10X to 100X that of the signal
`generated by the touching finger
`
`5Vdc
`
`5Vde
`
`5Vdc
`
`“Gnd”
`
`Source: Cypress
`
`ashigh
`lH A Cy |
`‘ r I t r non-EN
`
`chargers
`
`—
`
`as 60 V
`p-p for
`
`No common-modenoise
`
`Small common-mode noise
`
`Strong common-mode noise
`
`SID DISPLAY WEEK ‘14
`
`
`
`Noise Management...2
`
`*«* Examples of charger noise spectra
`+ Effect of noise is false or no touches, or excessive jitter
`
`
`
`RelativeMagnitude
`
`1
`
` J Narrow-band noise (chargerA)
`\
` Wide-band noise (charger B)|
`
`
`
`oO
`
`0
`
`100
`
`200
`
`300
`
`400
`
`500
`
`600 kHz
`
`Charger Noise Frequency
`
`Source: Cypress
`
`
`
`SID DISPLAY WEEK ‘14
`
`
`
`Noise Management...3
`
`«* Variation in common-modenoise spectra in 2
`different chargers at 3 different loads
`
`No load
`
`Load 50%
`
`Load 100%
`
`ChargerB ‘MHz!
`
`ChargerA
`
`SID DISPLAY WEEK ‘14
`
`Source: Cypress
`
`
`
`Noise Management...4
`
`«+ Techniques to combat charger noise
`+ Multiple linear and non-linearfilters
`+ Adaptive selection of the best operating frequency (hopping)
`+ Increased drive-electrode voltage
`e Going from 2.7 V to 10 V increases SNR by 4X
`+ Many proprietary methods
`
`«+ Display noise
`+ LCD noise is similar across the display; the high correlation of noise
`signals across all sensorsignals allows relatively easy removal
`+ Very high noise in embedded touch can require synchronization
`of the touch controller with the LCD driver (TCON)
`
`SID DISPLAY WEEK ‘14
`
`
`
`Controller Innovation Areas
`
`«* More information in upcoming slides
`+ Finger-hover
`+ Glove-touch
`+ Pressure sensing
`+ Other touch-objects
`+ Faster response (reduced latency)
`+ Adaptive behavior
`+ Water resistance
`+ Software integration
`+ Automated tuning
`
`¢¢ More information later in this course
`+ Passive and active stylus support
`
`SID DISPLAY WEEK ‘14
`
`rv)
`
`
`
`Finger-Hover...1
`
`«* There are two ways of emulating “mouseover” on
`a p-cap touchscreen
`+ Hover over something to see it change, then touch to select
`+ Presslightly on something to see it change, then press harder
`to select
`
`«* The industry is moving towards hover because nobody
`has beenable to implement pressure-sensing in a way
`that works well and that OEMsare willing to implement
`+ Startup: Nextinput
`e Force-sensing using an array of organic transistors where pressure
`changesthe gate current
`+ Startup: ZRRo
`e Multi-finger hover detection
`
`SID DISPLAY WEEK ‘14
`
`
`
`Finger-Hover...2
`
`«+ What can you do with hover?
`+ Enlarge small links when you hover over them
`+ Make a passive stylus seem to hoverlike an active stylus
`+ Magnify an onscreen-keyboard key as you approach
`rather than after you've touchedit, or even use a “Swipe”
`keyboard without touchingit
`+ Preview interactive objects such as an array of thumbnails
`+ Use as an alternative to standard proximity detection
`+ Use multi-finger gestures for more complex operations
`+ And more...
`
`SID DISPLAY WEEK ‘14
`
`rv
`
`
`
`Glove-Touch
`
`«+ Can be accomplished by
`adding self-capacitive to
`existing mutual-capacitive
`+ Mutual-capacitive provides
`touch location
`
`+ Self-capacitive provides
`proximity sensing
`+ Glove-touch causesthe finger
`to remain a constant distance
`above the screen; proximity
`sensing can detect that without
`the user manually switching
`modes
`
`
`
`
`
` Pass
`Pass
`
`
`
`SID DISPLAY WEEK ‘14
`
`
`
`
`
`Pressure Sensing
`
`«+ Pressure-sensing is an alternative selection method
`+ True absolute pressure-sensing in p-cap doesn’t exist today
`+ Some(including Microsoft) believe that “touch lightly to view
`choices then press to select’ is more intuitive than hover
`e It has never been implemented successfully in a mobile device
`» Blackberry Storm (2 models!) failed due to terrible implementation
`» Nissha/Peratech (QTC) collaboration never madeit into mass-production
`+ Multiple startups are working on smartphone pressure-sensing
`e Nextinput
`» Usesan array of pressure-sensitive organic transistors under the LCD
`e FloatingTouch
`» Mounts the LCD on pressure-sensing capacitors made using a 3M material
`
`SID DISPLAY WEEK ‘14
`
`
`
`Other Touch Objects
`
`** You will soon be able to touch with a fine-tipped (2 mm)
`passive stylus, long fingernails, a ballpoint pen, a #2
`pencil, and maybe other objects
`+ This is being accomplished through higher signal-to-noise
`(SNR)ratios
`e Muchof this improvement may come from enhancing the controller
`analog front-end in addition to focusing on the digital algorithms
`+ This enhancementto the UX will be the end of “finger-only” p-cap
`
`SID DISPLAY WEEK ‘14
`
`
`
`Faster Response
`
`«* Make touch more natural by reducing latency
`+ The shorter the time is between a touch and the response,
`the better the user feels about the touch system
`e lf an object lags behind yourfinger when you dragit, or ink lags
`behind a stylus when you’re drawing, it doesn’t feel real
`
`milliseconds
`
`+ Latency todayis typically 75-100 ms;
`studies have shown that humans
`need less than 10 ms for comfort
`
`e Synaptics has addressed the problem
`by creating a direct path between the
`touch controller and the TCON to
`allow limited instant screen updates
`e Tactual Labs (startup) has a method
`of reducing latency to just a few
`
`\Android
`~ lag!
`
` SID DISPLAY WEEK ‘14
`
`Source: Gigaom.com
`
`
`
`Adaptive Behavior: Noise Immunity
`
`** Adaptive noise-managementby N-Trig
`
`
`
` SID DISPLAY WEEK ‘14 49
`
`
`
`
`
`Water Resistance...1
`
`** The basic concept is combining self-capacitive and
`mutual-capacitive sensing (again)
`Self Y
`
`Water drops on the screen
`
`Source: ELAN
`GW O8W
`oC
`a
`oD
`ax]
`
`OEE
`OxD
`ED)
`ame
`==
`= = 2 Oo Oe
`
`oO ee ae KN oe med
`
`Wateris not detected
`in self-capacitive mode
` SID DISPLAY WEEK ‘14
`
`Wateris detected in
`mutual-capacitive mode
`
`
`
`Water Resistance...2
`
`«* A large amountof water with single-touch
`
`Self Y
`
`G00 :
` § Mutual
`
`166050 0000
`
`0000
`
`9200
`
`0000
`
`
`00ND OM 0000 ODN {
`
`0027
`
`9011
`
`
`SID DISPLAY WEEK ‘14
`
`0000 On 000 ODN {
`9003
`0020
`0000
`9200
`0000
`0000
`TP! oc21
`' 9010 ‘0000 ‘0000 © e900 0000 : 0020 : 9000 : ann: on00 :0000 : o0N0 ¢ Source: ELAN
`
`
`
`
`Water Resistance...3
`
`- 0095 70108 7G104- 0000<0000 0014 0010 aM |
`:
`ik
`:
`§
`
`‘ :
`
`
`
` Ded
`
`SID DISPLAY WEEK ‘14
`
`
`
`
`
`
`
`Dibe co0c | cn00 0000 | an00 and | 0000.cnN0 | c000 coND ante f Source: ELAN
`
`oY
`
`Qn,
`
`
`
`Software Integration
`
`¢* Make more resources available to the touch controller
`
`+ Run touch algorithms on the GPUinstead of the controller micro
`e Algorithm-writers can take advantage of muchlarger resources on
`the host device (MIPS and memory)
`
`"poweransunponeal’uppfretsonareget
`
`
`
`
`
`e Algorithmic code is easier and faster to change whenit’s in a “driver”
`than when it’s in firmware in an ASIC
`
`» Most touch-controller suppliers never change the firmware in the
`touch controller once it ships in a device; N-Trig is the sole exception
`e Cost-reduction by elimination of one micro
`» Even more cost reduction for large screens byelimination of slave chips
`+ Something similar to this has already been done in NVIDIA’s
`“Direct Touch’, but it hasn’t been widely used in actual devices
`
`SID DISPLAY WEEK ‘14
`
`
`
`Automated Tuning
`
`«+ For true “touch everywhere”, p-cap has to become
`like resistive: Just slap it on and you’re done
`+ We're far from that point today
`+ Atmel says that the typicalfirst integration of a p-cap touch-panel
`into a new product takes one full day of tweaking up to 200
`individual parameters
`+ That badly needs to be automated so that small commercial
`product-makers have easier access to p-cap
`
`SID DISPLAY WEEK ‘14
`
`
`
`P-Cap Controller Suppliers
`
`«+ In order by estimated 2013 revenue
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`fimagis[Korea
`
`
`
`Top 7 (30%)
`accountfor
`
`about 85% of
`total revenue
`
`And a few others...
`+ AMT
`+ Avago
`+ Pixcir
`
`7 STMED
`+ Weltrend
`
`
`
`
`
`SID DISPLAY WEEK ‘14
`
`EX
`
`
`
`
`
`“+ Substrates
`
`“+ Structures
`
`«+ Sheet vs. Piece Method
`
`«+ More on OGS
`“+ Glass Strengthening
`“* Surface Treatments
`** ITO Index Matching
`** Suppliers
`
`SID DISPLAY WEEK ‘14
`
`
`
`Sensor Substrates...1
`
`«- ITO film substrates are usually PET’ or COP?
`+ Thickness has dropped from 100 um to 50 um
`+ Lowest practical ITO sheetresistivity is currently ~100 QO/o
`
`** ITO glass substrates
`+ Standard thickness for GG is 0.33 mm and 0.4 mm
`
`+ Some makers have developed a thinning process(like for LCDs)
`that reduces glass thickness to 0.2 mm
`+ Corning and AGC have developed 0.1 mm glassbut it hasn't
`been used in volume sensorproduction yet
`+ Lowestpractical ITO sheetresistivity on glass is ~50 O/o
`
`SID DISPLAY WEEK ‘14
`
`1 = Polyethylene Terephthalate
`2 = Cyclic Olefin Polymer
`
`
`
`Sensor Substrates...2
`
`«* PET film versus glass
`
`Glass Transition Temperature
`Aging Effects
`
`Yellowing, curling,
`surface deformation
`
`570°C
`No knowneffect
`
`=>90%
`
`hicker
`eavier
`
`ood
`
`ion-exchange
`
`Mechanical Strengthening laniae Chemical, heat,
`
`Excellent
`
`SID DISPLAY WEEK‘14
`
`58
`
`intel)
`
`
`
`Sensor Structures...1
`
`«* Sensor structure abbreviations (for reference)
`
`G
`G
`
`Cover-glass (or plastic or sapphire
`Cover-glass, or sensor-glass with ITO on oneside, or
`plain glassforfilm lamination
`Cover-glass + one sensor-glass (without ITO location
`GG
`GGG|Cover-glass + two sheets of sensor-glass (rare
`# = Numberof ITO layers on oneside of sensor-glass
`G#
`G2 = “One Glass Solution” = OGS = SOC = SOL,etc.
`G1F|F = Sensor-film with ITO on oneside, laminated to glass
`GFF|FF = Two sensor-films, laminated to glass
`
`(LG Display’s hybrid in-cell/on-cell)
` 1 = Two ITO layers on oneside of sensor-film,
`
`laminated to glass (also called GF-Single)
`2 = One ITO layer on eachside of sensor-film,
`laminated to glass (also called GFxy with metal mesh)
`ITO on oneside of substrate (single-sided);
`usually includes metal bridges for Y to cross X
`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
`
`SID DISPLAY WEEK‘14
`
`59
`
`intel)
`
`
`
`Sensor Structures...2
`
`«* Glass-only structures
`
`OGS or SOC
`GG , G-DITO or G1G
`GG or G-SITO
`GGG
`Structure Names
`
`Comments|Single ITO layer on Single ITO layer ITO layer on each Single ITO layer
`
`
`eachpiece of glass;
`with bridges
`side of 1 glass; or ITO
`with bridges
`Obsolete
`
`on oneside of 2 glass Example Products
`
`Kindle Fire,
`B&N Nook;
`Nokia Lumia 800
`
`iPhone-1; iPad-1
`(GG); Lenovo AiOs
`GiG
`
`Google Nexus 4/7;
`Xiaomi2;
`Nokia Lumia 920
`
`Glass
`Glass
`Glass
`Adhesive_DriveElectrodes—
`
`-DriveElectrodes—
`
`Glass
`
`» SITO = Single-sided ITO layer; usually meansthere’s a bridge
`» DITO = Double-sided ITO layer (Apple patent)
`>» OGS = OneGlass Solution (Sensor on cover-glass)
`» SSG = Simple Sensor Glass (OGS without cover-glass shaping & finishing)
`
`
`
`SID DISPLAY WEEK ‘14
`
`
`
`Sensor Structures...3
`
`¢* Glass-and-film structures
`
`G1F
`Single ITO layer on
`glass; single ITO
`layer on film
`Example Products|Many Samsung
`products in 2013;
`Microsoft
`
`Structure Names
`
`Surface RT
`
`» Why would a touch-module maker use a sensorstructure
`that requires having both glass- and film-handling equipment?
`» One reasonis that there was a shortageof ITO film in 2013
`
`
`
`SID DISPLAY WEEK ‘14
`
`
`
`Sensor Structures...4
`
`
`«* Film-only structures
`
`
`
`Structure Names
`Comments
`
`GF Triangle
`Bare glass and two
`Bare glass with true
`Bareglass with true
`single-sided ITO films;
`single-layer complex
`single-layertriangle
`performance is better
`pattern on film
`pattern on film
`than GF1
`e.g.,
`“caterpillar”
`(e.g., “backgammon”)
`Example Products|Samsung Galaxy Tabs Apple iPads; next Many low-end Low-end products with
`
`
`
`
`
`and Notes; Google iPhoneif Apple can’t get|smartphones, especially “gesture touch”, not
`Nexus 10
`good yield on in-cell
`in China
`multi-touch
`
`GF2 or DITO-Film
`Bare glass and one
`double-sided
`ITO film
`
`» Single-layer caterpillar pattern is used to support “real” multi-touch with 2-3
`touches,typically in a smartphone(that’s not enough touchesfor a tablet)
`» Single-layer backgammonpattern is used to support “gesture touch” on
`low-end devices, i.e., the ability to detect pairs of moving fingers but not
`always resolve two stationary touches
`SID DISPLAY WEEK ‘14
`62
`
`Te
`
`
`
`Sensor Structures...5
`
`** Why do touch-module makers choose one structure
`over another?
`
`+ Transmissivity
`+ Thickness & weight
`+ Border width dueto routing
`+ Cost & availability of ITO film or deposition
`+ Lamination experience & yields
`+ Existing equipment and/or method experience
`
`SID DISPLAY WEEK ‘14
`
`
`
`Sensor Structure by Application
`
`Smartphones
`
`GF Triangle
`GG DITO
`
`Tablets & Notebooks
`
`All-in-Ones
`
`GF1/Single-Layer
`
`Data based on DisplaySearch’s “Q1-2014 Quarterly Touch-Panel
`Market Analysis Report’, with adjustments by the author
`
`
`
`SID DISPLAY WEEK ‘14
`
`
`
`Sheet vs. Piece Method...1
`
`(Wintek Sheet Example - OGS)
`
`SID DISPLAY WEEK ‘14
`
`Source: Wintek
`
`oS
`
`Gee
`
`
`
`Sheet vs. Piece Method...2
`(Wintek Piece Example - Discrete)
`
`
`
`SID DISPLAY WEEK ‘14
`
`Source: Wintek
`
`or
`
`Tee
`
`
`
`More On OGS
`
`** One-Glass Solution (OGS)
`+ Also called “touch on lens” (TOL), “sensor on cover” (SOC),
`“direct patterned window” (DPW) and many other names
`+ Advantages
`e Eliminates a fourth sheet of glass (G-DITO), making the end-product
`thinner and lighter
`e Competitive weapon against embedded touch from LCD suppliers
`+ Disadvantages
`e Requires close cooperation with cover-glass makers, or increased
`vertical integration (preferable)
`e Yields are lower (more complex operations)
`e Bendable cover glass can affect touch performance
`e Harder to shield touchscreen from LCD noise
`
`+ Note: There is no generic name (yet) for touch sensors built on the
`cover-glass without direct ITO deposition (“OGS-type”)
`SID DISPLAY WEEK ‘14
`67
`
`intel)
`
`
`
`Glass Strengthening
`
`«+ Heat strengthened
`+ Less-rigorous version of fully tempered; does not “dice” when
`broken; 2X as strong as standard glass
`“* Fully tempered
`+ Uses heat; requires glass > 3 mm, so not used for consumer
`touchscreens; glass “dices” when broken (think auto windows);
`4X to 6X as strong as standard glass
`«* Chemical strengthened (CS)
`+ Uses ion-exchangein a salt bath; best for glass < 3mm; glass does
`NOT “dice” when broken; 6X to 8X as strong as standard glass
`“+ High ion-exchange aluminosilicate glass
`+ 6X to 8X as strong as standard glass (same as CSglass)
`+ Corning Gorilla®, Asahi Dragontrail™, Schott Xensation™
`
`SID DISPLAY WEEK ‘14
`
`SS)
`
`Toy
`
`
`
`Sensor Surface Treatments...1
`
`«+ Historically most commontreatmentis anti-glare (AG)
`+ Changesspecularreflection into diffuse reflection
`+ Used mostly for commercial & enterprise, not consumer(“glossy”)
`+ Three methods, roughly equal cost
`e Chemical etching
`e Application of sol-gel containing silica particles
`e Mechanical abrasion
`
`+ Level of anti-glare can be very little to a lot
`
`«* Anti-fingerprint (AF) treatmentis rapidly growing
`+ Many different forms (spray-on, rub-on, sputter, etc.); also
`called “anti-smudge’”(AS)
`+ DemandIs increasing
`+ Cost is dropping (currently ~$8.50/m2)
`SyDEPSVANaaene
`re
`
`intel)
`
`
`
`Sensor Surface Treatments...2
`
`«* Anti-reflection (AR) treatmentis still a problem
`+ Reduces specularreflection to range of 2% to 0.4%
`+ Durability is typically < 1 year
`+ It’s expensive (currently ~$34.50/m2)
`+ Yetit’s really important for outdoor viewing, particularly of
`consumers’ glossy screens (ideal is AF+AR = ~$43/m2)
`
`«+ Other coatings are available but less common
`+ Anti-corruption (allows permanent Sharpie ink to be wiped off)
`+ Anti-microbial/anti-bacterial (AM/AB, for healthcare applications)
`+ Hard coating (can be made upto 9H for glass-like anti-scratch)
`+ Anti-stiction (reduces finger-sticking friction)
`+ Anti-crack coating (increases durability at lower cost than Gorilla
`glass; uses atomic layer deposition [ALD])
`
`SID DISPLAY WEEK ‘14
`
`
`
`ITO Refractive-Index Matching
`
`** Reducethe reflectivity of ITO by compensating for the
`difference in index of refraction of ITO vs. glass/PET
`«+ Limited to 2 layers on PET; more can be used on glass
`+ Alternating layers of material with low and high refractive index
`+ Layer thicknesses(typically between % and % of the wavelength
`of light) are chosen to produce destructive interferencein reflected
`light, and constructive interference in transmitted light
`
`ITO (RI = ~2.0)(-
`
`TiO, (RI = 2.48) (eee
`
`SiO, (RI = 1.45) [eee
`
`Glass (RI = 1.52)PeT(alsie)L
`
`Source: The author
`
`SID DISPLAY WEEK ‘14
`
`if
`
`
`
`Sensor Suppliers
`
`** Many touch-module makers manufacture their
`own sensors
`
`+ The remainder are madebythe following companies,
`in order by estimated 2013 revenue
`
`ihePacing[ee
`
`
`
`InnoluxsfTaiwan | (China)
`
`Andat least one more...
`
`(DNP.—CSCidattr.
`
`
`
`SID DISPLAY WEEK ‘14
`
`
`
`ITO-Replacement Materials
`
`oe
`
`5O
`
`Metal Mesh
`
`oe
`
`Silver Nanowires
`
`Carbon Nanotubes
`Conductive Polymers
`
`oe
`
`oe
`
`OS
`
`fe
`
`SID DISPLAY WEEK ‘14
`
`
`
`ITO Replacements...1
`
`«+ Whyreplace ITO?
`+ Costly to pattern & needs high temperature processing
`+ Highly reflective (IR = 2.6) & tinted yellow;brittle & inflexible
`+ NOT because we're going to run outofit!
`** Replacement material objectives
`+ Solution processing (no vacuum, no converted LCD fab)
`+ Better performancethan ITO (transmissivity & resistivity)
`+ Lower material & process cost than ITO
`“+ Five replacement candidates
`+ Metal mesh
`+ Silver nanowires
`+ Carbon nanotubes
`+ Conductive polymers
`+ Graphene
`
`SID DISPLAY WEEK ‘14
`
`
`
`ITO Replacements...2
`
`«+ [TO-replacement materials are having a definite
`market impact — 11% in 2014!
`+ See the latest IHS market report on non-ITOfilms
`
`NontTO film market share by film type (2014)
`
`ITO Film
`89%
`
`11%
`
`Non-ITO Film
`
`+ Ag halide is simply
`another method of
`making a silver mesh,
`so the meshtotal is
`85% vs. 15% for
`nanowire
`
`+ The value is performance and cost
`e Both unit cost and CAPEX
`
`
`
`SID DISPLAY WEEK ‘14
`
`
`
`Metal Mesh...1
`
`** Metal mesh is shipping in touchscreens,andit’s
`looking very promising!
`«+ Brief history of first-movers
`+ MNTechin Korea wasthefirst to ship metal-mesh at the
`end of 2012 — but their factory burned down
`+ Atmel(partnered with CIT in the UK) was the secondto ship metal-
`mesh (XSense™) for a smartphone anda 7” tablet in 1H-2013
`+ FujiFilm started production of their silver-halide-based
`metal-mesh product in 2Q-2013
`
`SID DISPLAY WEEK ‘14
`
`
`
`Metal Mesh...2
`
`
`
`4-5 mm senseelectrode (bottom surface)
`<_————__—_—_—___—_>
`
`SS eS ee=, s
`7
`“dA
`
`4-6 um wide
`
`conductors
`with spacing
`of 100-400 um
`
`4-5 mm
`drive
`electrode
`(top surface)
`
`Intentional
`gapsin lines
`
`the author
`
`Top
`layer
`(red)
`
`Bottom
`layer
`(white)
`
`I
`Source: 2 “pe Ss
`Photo by Unipixel, “S|
`ee
`a oe
`annotation by»
`
` SID DISPLAY WEEK ‘14
`
`(intel)
`
`
`
`Metal Mesh...3
`
`** Metal mesh hassignificant advantages
`+ Patterning via roll-to-roll printing allows both operating and
`capexcostto be very low—it’s going to beat bothlitho andlaser!
`e Electrodes and border connections are printed simultaneously,
`which allows borders as narrow as 3 mm (typically 9 mm with ITO)
`+ Sheetresistivity is much lower than ITO (under 10 ohms/square)
`e Reduces p-cap charge time, which allows larger touchscreens
`+ Transparencyis better than ITO
`+ Meshpattern creates electrical redundancy, which improvesyields
`+ Highly flexible — bend radius typically 4 mm
`
`SID DISPLAY WEEK ‘14
`
`
`
`Metal Mesh...4
`
`«* O-film is t