Touchscreen Tutorial

Transcription

1 Touchscreen Tutorial Presented by a Team of Touch Experts from 3M, Elo TouchSystems, Fujitsu & Walker Mobile SID 2007 Display Applications Conference Touchscreen Session 1

2 Session Objective Present practical, vendor-independent information that a project engineer can use to select, buy, integrate and test a touchscreen for a product today SID 2007 Display Applications Conference Touchscreen Session 2

3 Presentation Team T Geoff Walker ) Principal Consultant, Walker Mobile T Frank Lung ) Product Manager, Elo TouchSystems T James Roney ) Manager of Touchscreen Development, Elo TouchSystems T Ken Miller ) Global Technical Service Manager, 3M Touch Systems T Bruce DeVisser ) Product Marketing Manager, Fujitsu Components SID 2007 Display Applications Conference Touchscreen Session 3

4 Agenda T Part 1 ) Introduction (Geoff) ) How the mainstream touch technologies work (Geoff) ) How to select a mainstream touch technology (Frank & James) ) Q&A session #1 (All) Break (15 minutes) T Part 2 ) How the emerging touch technologies work (Geoff) ) Customization (Ken) ) Integration (Ken) ) Test plans & methods (Bruce) ) Purchasing components (Bruce) ) Gotchas (Bruce) ) Q&A session #2 (All) SID 2007 Display Applications Conference Touchscreen Session 4

5 Touch Technologies We Are Covering T Mainstream (primary focus) ) Analog resistive ) Surface capacitive ) Surface acoustic wave (SAW) ) Infrared (IR) T Emerging (secondary focus) ) Projected capacitive (ITO-based & wire-based) ) Optical (camera-based) ) Acoustic pulse recognition (APR bending wave look-up) ) Dispersive signal technology (DST bending wave processing) SID 2007 Display Applications Conference Touchscreen Session 5

6 Touch Technologies We Are Not Covering T Future (not available yet) ) Optical waveguide infrared (from RPO) ) Force-sensing (from QSI) ) In-pixel (light- & capacitive-sensing, from LCD manufacturers) T Other ) Frustrated total internal reflection (FTIR, used with rear projection) ) Laser-pointer touch (e.g., from Keytec, used with front projection) ) Active digitizers (e.g., from Wacom, used in Tablet PCs) ) Haptics (e.g., VibeTonz from Immersion, used in cellphones) ) Opaque touch (e.g., from Quantum, used for control surfaces) SID 2007 Display Applications Conference Touchscreen Session 6

7 How the Mainstream Touch Technologies Work (Geoff Walker) SID 2007 Display Applications Conference Touchscreen Session 7

8 Analog Resistive Photo courtesy of Engadget SID 2007 Display Applications Conference Touchscreen Session 8

9 Analog Resistive 1 (ITO) (PET) Illustration courtesy of Bergquist Illustrations courtesy of Elo TouchSystems SID 2007 Display Applications Conference Touchscreen Session 9

10 Analog Resistive 2 T Types ) 4-wire (low cost, short life) is common in mobile devices ) 5-wire (higher cost, long life) is common in stationary devices T Constructions ) PET + Glass (previous illustration) is the most common ) PET + PET is the thinnest; sometimes used in cellphones ) Glass + Glass is the most durable; gaining share in automotive ) Film-film-glass, others T Options ) Surface treatments (AG, AR, AS), rugged substrate, dual-force touch, high-transmissivity, surface armoring, others Illustration courtesy of Schott SID 2007 Display Applications Conference Touchscreen Session 10

11 Analog Resistive 3 T Size range ) 2 to ~26 T Major applications ) Mobile devices ) Point of sale (POS) terminals T 2006 market share ) 89% by volume ) 73% by revenue T Market leaders Note: All market share numbers in this presentation are estimates by Walker Mobile. ) Elo TouchSystems, Fujitsu, Gunze, Touch International ) 50+ suppliers worldwide SID 2007 Display Applications Conference Touchscreen Session 11

12 Surface Capacitive Illustration courtesy of 3M SID 2007 Display Applications Conference Touchscreen Session 12

13 Surface Capacitive 1 Tail Scratch-resistant top coat Hard coat with AG Electrode pattern Illustration courtesy of Elo TouchSystems Conductive coating (ATO, ITO or TO) Glass Optional bottom shield (not shown) Illustrations courtesy of 3M SID 2007 Display Applications Conference Touchscreen Session 13

14 Surface Capacitive 2 T Size range ) 6.4 to 32 T Major applications ) Gaming & entertainment ) Kiosks ) ATMs T 2006 market share ) ~5% by volume ) ~13% by revenue T Market leaders ) 3M, DigiTech ) 16+ suppliers worldwide Illustrations courtesy of 3M SID 2007 Display Applications Conference Touchscreen Session 14

15 Surface Acoustic Wave Illustration courtesy of Kodak SID 2007 Display Applications Conference Touchscreen Session 15

16 Surface Acoustic Wave 1 Glass substrate (45 ) Rayleigh wave Illustrations courtesy of Onetouch (left) and A-Touch (right) SID 2007 Display Applications Conference Touchscreen Session 16

17 Surface Acoustic Wave 2 T Size range ) 8 to 50 T Major applications ) Kiosks ) Gaming & entertainment T 2006 market share ) 2% by volume Photo courtesy of Euro Kiosks Network ) 6% by revenue T Market leaders ) Elo TouchSystems, General Touch ) 10+ suppliers worldwide SID 2007 Display Applications Conference Touchscreen Session 17

18 Infrared Photo courtesy of IBM SID 2007 Display Applications Conference Touchscreen Session 18

19 Infrared 1 Illustrations courtesy of Elo TouchSystems SID 2007 Display Applications Conference Touchscreen Session 19

20 Infrared 2 T Size range ) 8 to 150 T Major applications ) Kiosks ) Large displays T 2006 market share ) 2% by volume ) 5% by revenue T Market leaders ) Elo Touch, IR Touch ) 16+ suppliers 50 plasma display with infrared touchscreen from Netrax SID 2007 Display Applications Conference Touchscreen Session 20

21 How to Select a Mainstream Touch Technology (Frank Lung & James Roney) SID 2007 Display Applications Conference Touchscreen Session 21

22 Agenda T Methodology T Benefits of touch (review) T Input models T Considerations T Application examples T Touch technology +/- SID 2007 Display Applications Conference Touchscreen Session 22

23 Methodology T Focus on existing high-volume technologies ) Resistive, surface capacitive, surface acoustic wave & infrared T Focus on functionality & characteristics rather than specifications ) Methods in which a user is interacting with the touch application is the key factor in considering the best touch technology to be used T Decision based on usage, application and/or environmental needs ) Use-model carries several requirements ) There s no perfect touch technology that meets all requirements ) One must consider (and prioritize) the technology which accommodates the most critical needs SID 2007 Display Applications Conference Touchscreen Session 23

24 Designers: Generally Two Types This presentation focuses here! T I m just starting ) Need to know benefits & considerations ) Let me see all the options T I m using touch now ) I know what I want ) And I know what I don t want! SID 2007 Display Applications Conference Touchscreen Session 24

25 General Benefits of Touch 1 T Natural input device ) Ease of use ) Public friendly T The only interface that is direct vs. indirect ) Not distracted by input device ) Invisible device ) Eyes stay on the screen ) Fast! T Intuitive ) Everyone can touch ) No experience needed ) No manual ) No computer literacy )...Or even literacy needed SID 2007 Display Applications Conference Touchscreen Session 25

26 General Benefits of Touch 2 T Guides the user T Limits choices ) Not all options at once; less chance of mistakes T Reconfigurable by changing the application T Mature product T Affordable T Best device for ) Public ) Average employee (non-computer user) ) Data retrieval applications, not data entry or general PC use T Touch is (new) fun! SID 2007 Display Applications Conference Touchscreen Session 26

27 Not-So-Obvious Benefits of Touch 1 T Compact ) Takes less space than a keyboard or a mouse T Self-illuminating T Learning is easier: ) Reduced training time ) More retention T Works with glove & anything compatible ) ADA ) Voting T Rugged ) More durable than keyboards, mice, track balls, membrane keypads SID 2007 Display Applications Conference Touchscreen Session 27

28 Not-So-Obvious Benefits of Touch 2 T Easy to clean and sterilize T Lower total cost ) Reduced training, faster speed, etc. T Touch systems ) 24-hour access and availability ) Multi-lingual More engaging for the user! SID 2007 Display Applications Conference Touchscreen Session 28

29 Typical Input Models T Finger-only ) Use for selecting large features with finger ) Usage with gloves should be considered T Finger + available objects ) Use for selecting large or small features with common objects ) It should allow many common items to be used as a stylus T Stylus-only ) The touch system is used for selecting small features with a stylus and can also be used for other functions such as handwriting recognition ) A special stylus may or may not be acceptable O Consider tethering ) Palm rejection is advantageous SID 2007 Display Applications Conference Touchscreen Session 29

30 High-Level Considerations 1 T Total cost of ownership ) Consider initial purchase price plus long-term costs including operation and maintenance T Accepted input devices ) Is it important that the application work with a finger, a gloved finger, a metal stylus, a nonconductive stylus, a credit card, and/or a long fingernail? T Durability ) How harsh is the intended environment? ) Will it be used in the public sector (vandal considerations)? SID 2007 Display Applications Conference Touchscreen Session 30

31 High-Level Considerations 2 T Image quality of the underlying display ) Are clarity, brightness and readability of the display important to the application? ) If it will be used in very high ambient light, consider the effect of glare and contrast T Sealability and Chemical Resistance ) Is the screen/device likely to be subjected to spills and/or cleaning with harsh chemicals? T Reliability ) What is the impact of any downtime for repair? SID 2007 Display Applications Conference Touchscreen Session 31

32 Functionality & Characteristics T Ambient light sensitivity T Calibration stability T Controller chip T Cost T Curved substrate T Debris/contamination T Design T Drag performance T Durability T Ease of integration T Flush surface T Handwriting recognition T HID interface T Hover T Lifetime/MTBF T Mobile/handheld T Multi-touch T Non-glass substrate T Object size recognition T Optical clarity T Reliable light touch T Scratch resistance T Sealability T Screen size T Stylus independence T Vandal resistance T Weather resistance T Z-Axis measurement Anticipate undiscovered needs! SID 2007 Display Applications Conference Touchscreen Session 32

33 Characteristics & Scoring 1 Characteristic Resistive (4-wire) Resistive (5-wire) Surface Capacitive Surface Acoustic Wave Ambient Light Sensitivity Calibration Stabilty Controller Chip Cost Curved Substrate Debris/Contamination Drag Performance Durability Ease of Integration Flush Surface Handwriting Recognition HID Interface Hover Lifetime/MTBF Mobile/Handheld Infrared 0 = Not applicable 1 = Least appropriate 5 = Most appropriate ) Weight & rank based on relevance to the application ) There will be trade-offs! SID 2007 Display Applications Conference Touchscreen Session 33

34 Characteristics & Scoring 2 Characteristic Resistive (4-wire) Resistive (5-wire) Surface Capacitive Surface Acoustic Wave Multi-Touch Non-Glass Substrate Object Size Recognition Optical Clarity Reliable Light Touch Scratch Resistance Sealability Size >50" Size 30" - 50" Size 12" - 28" Size 2" - 10" Stylus Independence Vandal Resistance Weather Resistance Infrared 0 = Not applicable 1 = Least appropriate 5 = Most appropriate ) Weight & rank based on relevance to the application ) There will be trade-offs! SID 2007 Display Applications Conference Touchscreen Session 34

35 Prioritized for Each Application Transactional T Untrained T Optional users T Familiar Obligatory T Required users T Image clarity ) Attract and sell T Vandal & scratch-resistant T Others? T Based on past usage ) Untrained T Any stylus ) Gloves, pen, fingernail, credit card, etc. T IP65, NEMA 4 sealable T Others? SID 2007 Display Applications Conference Touchscreen Session 35

36 Transactional Applications T Kiosks ) Point of information (POI) ) Merchandising ) Tourism & museums ) Gift registries ) Digital photo printing stations T Ticketing & vending T Financial T Transportation T Gaming/amusement T Telecommunication ) Web phones ) Internet terminals T Outdoor ) Gas pumps ) ATMs ) Outdoor vending machines ) Store window applications SID 2007 Display Applications Conference Touchscreen Session 36

37 Obligatory Applications T Point of sale (POS) ) Restaurants ) Hospitality ) Post offices T Industrial/process control T Medical equipment T Office equipment ) Time clocks ) Copiers T Retail T Automotive ) Navigation ) Diagnostic systems T Personal mobile device Photo courtesy of Engadget SID 2007 Display Applications Conference Touchscreen Session 37

38 Market Needs: Examples T General ) Easy employee training ) Fast, simple transactions ) Rugged, durable, reliable ) Watertight seal ) Small footprint & floor space T POS ) Any stylus (credit card, fingernail,etc.) ) Works when wet T Medical ) Gloves ) No glass ) Easy to sterilize T Industrial ) Gloves ) Fast alarm acknowledgements ) Wash-down ) Specific agency approvals O NEMA 4; IP 65 High-pressure hose O O NEMA 12: IP54 Dust-proof, splash-proof Factory Mutual (FM) Intrinsically safe ) No glass in food processing SID 2007 Display Applications Conference Touchscreen Session 38

39 4 & 5-Wire Resistive 1 T Advantages ) Size ranges O 4-wire: 2 15 O 5-wire: ) Can be activated with any device or stylus ) Highly resistant to screen contaminates ) Sealability (NEMA) ) Low power consumption (4-wire) ) Multiple vendors for screen, controller & chip solution ) Cost of solution: Lowest (4-wire) SID 2007 Display Applications Conference Touchscreen Session 39

40 4 & 5-Wire Resistive 2 T Disadvantages ) Lower durability compared to other technologies, especially considering cosmetic wear ) Poorer transmittance and overall optical quality due to plastic overlay and multiple layers ) May require periodic recalibration (4-wire) T Take-away ) Used in more applications than any other touch technology ) Input flexibility, sealability (NEMA) and cost SID 2007 Display Applications Conference Touchscreen Session 40

41 Typical Applications for 4-Wire Resistive T Applications ) Light industrial, portable medical devices, access control terminals, portable devices for field automation, wearable computers, home appliances, office equipment T Requirements ) Battery operation Must be low power ) Small size < 6-8 ) Low cost % of total system cost, high-volume ) Small footprint Small borders, thin ) Drop test No glass allowed? ) Lightweight Plastic? ) Highly customized ) Stylus Signature capture? ) Outdoor usage -- Sunlight readable, waterproof? ) Simple controller chip Or no controller? SID 2007 Display Applications Conference Touchscreen Session 41

42 Typical Applications for 5-Wire Resistive T Applications ) Hospitality & retail ) Medical ) Industrial ) Voting machines ) Office automation T Requirements ) Large displays >10 ) Indoor, controlled environment ) Touch response & stylus flexibility ) Liquid and residue resistance ) NEMA sealing ) Calibration stability (over 4-wire) ) Low cost SID 2007 Display Applications Conference Touchscreen Session 42

43 Surface Capacitive 1 T Advantages ) Size range: 3-32 ) More durable than resistive because the top layer isn t plastic ) Higher light transmission vs. resistive (fewer layers) ) Highly sensitive (touch & drag) ) Liquids & common contaminants don t impede performance ) Multiple vendors for screen & controller; chip solution limited ) Cost of solution: Moderate SID 2007 Display Applications Conference Touchscreen Session 43

44 Surface Capacitive 2 T Disadvantages ) Accepts input from finger only (or a tethered conductive stylus) ) Susceptible to electromagnetic interference (EMI) ) Accuracy may be affected by environment ) May requires periodic calibration T Considerations ) Common in bar-top, casino & amusement gaming ) Sensitive, resistant to everyday contaminants SID 2007 Display Applications Conference Touchscreen Session 44

45 Typical Applications for Surface Capacitive T Applications ) Casino & amusement gaming ) Self-checkout ) Ticketing & vending T Requirements ) Displays >15 to 32 ) Indoor, high contaminate ) Dirt and spill sealed ) Sensitive, light touch ) Good optics for games SID 2007 Display Applications Conference Touchscreen Session 45

46 Surface Acoustic Wave (SAW) 1 T Advantages ) Sizes Range from: 6 to 50 ) Very high transmittance O Only glass between end-user and image ) Very high durability O No wear mechanism O Functions even with scratches ) Finger, gloved hand and soft stylus activation ) Vandal tempered or chemically strengthen glass ) Multiple vendors for screen & controller; chip solution limited ) Cost of solution: Moderate SID 2007 Display Applications Conference Touchscreen Session 46

47 Surface Acoustic Wave 2 T Disadvantages ) Sealing is challenging ) Requires soft input device ) Surface obstructions or water can cause a false touch T Considerations ) Widely used in kiosk, gaming and home/office automation ) No wear mechanism ) Very high transmittance SID 2007 Display Applications Conference Touchscreen Session 47

48 Typical Applications for Surface Acoustic Wave T Applications ) Photo kiosks ) Airport & hotel check-in/out ) Gaming ) Home automation T Requirements ) Large displays >15 ) Very high transmittance ) No wear mechanism ) Indoor, controlled-to-low contaminate environment SID 2007 Display Applications Conference Touchscreen Session 48

49 Infrared (IR) 1 T Advantages ) Sizes Range from: 8 to 50 ) Can be activated with almost any device ) Very high transmittance O Only glass between end-user and image ) Very high durability O No wear mechanism ) Sealability (NEMA) ) With acrylic overlay, sole solution for glass-free applications ) Multiple vendors for screen & controller; chip solution limited ) Cost of solution: High (tooling & time) SID 2007 Display Applications Conference Touchscreen Session 49

50 Infrared 2 T Disadvantages ) Lower resolution than other technologies ) Surface obstructions or hover can cause a false touch ) Industrial design (bulkiest bezel) T Considerations ) POS, in-car/flight entertainment ) Input flexibility, sealability (NEMA) SID 2007 Display Applications Conference Touchscreen Session 50

51 Typical Applications for Infrared T Applications ) POS ) Automotive ) In-flight T Requirements ) Large displays >15 ) Very high transmittance ) No wear mechanism ) Glass-free applications ) Stylus flexibility SID 2007 Display Applications Conference Touchscreen Session 51

52 Summary T Know your users T Weight & rank touch technology characteristics based on relevance to the application T Understand trade-offs T Touch technology is advancing all the time SID 2007 Display Applications Conference Touchscreen Session 52

53 Question & Answer Session #1 SID 2007 Display Applications Conference Touchscreen Session 53

54 SID 2007 Display Applications Conference Touchscreen Session 54

55 How the Emerging Touch Technologies Work (Geoff Walker) SID 2007 Display Applications Conference Touchscreen Session 55

56 Projected Capacitive Photo courtesy of Apple SID 2007 Display Applications Conference Touchscreen Session 56

57 Projected Capacitive 1 (Apple iphone & ipod Touch) SID 2007 Display Applications Conference Touchscreen Session 57

58 Projected Capacitive 2 T Technology variations ) Two-layer sensor (X-Y grid) O Imaging or mutual capacitance [Apple s term] (iphone) O Non-imaging (Synaptics notebook touchpad) ) Single-layer sensor O Self capacitance [Apple s term] T Sensor variations ) Glass with ITO traces on both sides (iphone & ipod Touch) ) Two pieces of PET with ITO traces on one side each, laminated together, or a single piece of PET with traces on one side only (3M, Touch International, others) ) 10-micron wires laminated between two sheets of glass or PET (Zytronic, Visual Planet) SID 2007 Display Applications Conference Touchscreen Session 58

59 Projected Capacitive 3 T Size range ) 2 to T Major applications ) Apple iphone and ipod Touch (2007) ) Signature-capture POS terminals ) Outdoor ATMs, through-glass interactive retail signage, military devices T 2006 market share ExtremeTouch from Touch International ) 1% by volume ) 2% by revenue T Market leaders ) Balda/TPK/Optera, 3M, Synaptics, Wintek, Touch International, Zytronic ) ~12 suppliers as of 9/07 (rapidly increasing) Omni 7100 MPD Payment Terminal from Verifone SID 2007 Display Applications Conference Touchscreen Session 59

60 Optical This picture was drawn on a 46" LCD equipped with a NextWindow optical touchscreen by a visitor to the AETI Exhibition in London on January 24, Illustration courtesy of NextWindow SID 2007 Display Applications Conference Touchscreen Session 60

61 Optical 1 Illustrations courtesy of NextWindow SID 2007 Display Applications Conference Touchscreen Session 61

62 Optical 2 T Size range ) 12 to 120 T Applications ) HP TouchSmart (19-inch all-in-one family computer ) ) Large displays T 2006 market share ) 1% by volume ) 1% by revenue T Market leaders ) NextWindow, Smart Technologies (only 2 suppliers) Illustration courtesy of HP Illustration courtesy of NextWindow SID 2007 Display Applications Conference Touchscreen Session 62

63 APR & DST (Bending Wave) Illustration courtesy of 3M SID 2007 Display Applications Conference Touchscreen Session 63

64 Bending Wave (APR) 1 Method: Table look-up of 10ms touch signatures Illustrations courtesy of Elo TouchSystems SID 2007 Display Applications Conference Touchscreen Session 64

65 Bending Wave (DST) 2 Method: Real-time analysis of bending waves ( time of flight ) Illustration courtesy of 3M SID 2007 Display Applications Conference Touchscreen Session 65

66 Bending Wave 3 T Size range ) Elo/APR: Currently 15 to 19 ; future expansion smaller & larger ) 3M/DST: 32 to 60 T Major applications ) Elo/APR: Currently POS; could eventually replace most resistive ) 3M/DST: Large displays in interactive digital signage T 2006 market share ) Elo/APR: < 1% (first production in 9/06) ) 3M/DST: 0% (first production 4/07) T Market leaders ) Elo, 3M (only 2 suppliers) SID 2007 Display Applications Conference Touchscreen Session 66

67 Customization (Ken Miller) SID 2007 Display Applications Conference Touchscreen Session 67

68 Custom vs. Standard T Standard products ) Off-the-shelf, inventory part number ) No NRE (non-recurring Engineering) fees ) Low or No minimum quantity requirements ) Less expensive on a per unit basis T Custom products ) Customer-specific request O Purchaser bears responsibility for defining requirements ) Longer leadtimes ) NRE fees can range from $2,000 - $10,000 (supplier-dependent) ) Minimum quantities often required ) Typically more expensive on a per unit basis ) Single-source limitation ) Ownership and control SID 2007 Display Applications Conference Touchscreen Session 68

69 General Substrate Product R General substrate product (Includes resistive, surface capacitive, projected capacitive & surface acoustic wave) ) Cable exit location ) Cable length ) Size and aspect ratio SID 2007 Display Applications Conference Touchscreen Session 69

70 Custom Product Specifics 1 T Resistive ) EMI shielding ) Gaskets ) Graphics ) Membrane switches ) Palm rejection O Stylus only ) Extended touch life ) High light transmission ) Product differentiation O Branding, logos, company colors Adjust spacer dots to accommodate palm rejection or pen Custom Product SID 2007 Display Applications Conference Touchscreen Session 70

71 Custom Product Specifics 2 T Resistive (continued) Silk-screened graphics Brand with logos or product names Membrane switches SID 2007 Display Applications Conference Touchscreen Session 71

72 Custom Product Specifics 3 T Surface capacitive ) Impact resistant ) Privacy viewing ) Tethered pen ) Rear shield ) Anti-glare (AG) coating Impact resistant 3M Privacy Monitor Laminated privacy film Blocked View Blocked View Clear View Tethered pen SID 2007 Display Applications Conference Touchscreen Session 72

73 Custom Product Specifics 4 T Surface acoustic wave ) Ruggedized ) Privacy viewing ) Special coatings ) Rear shield Ruggedized touch Laminated privacy film 3M Privacy Monitor Blocked View Blocked View Clear View Tempering Chemical or heat strengthening SID 2007 Display Applications Conference Touchscreen Session 73

74 Custom Product Specifics 5 Touch Technology Custom Feature Resistive Surface Capacitive Projected Capacitive Surface Wave Infrared Optical Touch Screen Size x x x x x x Cable Exit Location x x x x x x Cable Length x x x x x x Gaskets x x x x x x Surface Treatment x x x x x x Ruggedized x x x x x x EMI Shielding x Graphics x Membrane Switches x Palm Rejection x Cable Connector x X = Custom feature typically available SID 2007 Display Applications Conference Touchscreen Session 74

75 Integration (Ken Miller) SID 2007 Display Applications Conference Touchscreen Session 75

76 Integration Touch system includes touch sensor, controller and software Sensor and controller Software drivers SID 2007 Display Applications Conference Touchscreen Session 76

77 Substrate Technology Integration Basics 1 R Touch screen fit R Gasket seal R Touchscreen alignment R Touchscreen mounting Gasket Seal Touch Screen Mounting Tape LCD Bezel SID 2007 Display Applications Conference Touchscreen Session 77

78 Substrate Technology Integration Basics 2 T Route the touchscreen cable away from the LCD backlight inverter T Eliminate stress in the touchscreen cable through handling and integration T Design your touchscreen integration with the cable exiting from the top or sides of the display. ) Cable exits from the bottom may allow spills to accumulate in the tail attachment area, causing electrical shorting T Apply tape or other insulating material to sharp edges to protect the cable ) Route the cable away from sharp edges whenever possible; if this cannot be avoided, secure the cable to prevent movement SID 2007 Display Applications Conference Touchscreen Session 78

79 Resistive Integration Considerations T Mount the touch screen to the LCD not the bezel ) Thermal coefficient difference in the materials can cause stress to the touch screen s top sheet, causing a pillowing effect T Alignment or registration of the touchscreen to the bezel is critical ) Bezel pressure exerted to the active area of the touch screen will cause a constant touch condition. O Apply gasket material to the non-active portion of the touchscreen to guard against bezel misalignments SID 2007 Display Applications Conference Touchscreen Session 79

80 Surface & Projected Capacitive Integration Considerations T For the use of touchscreens without a rear shield, ensure that the touchscreen is fixed into position and has no movement T Metal bezel (includes bezels containing conductive paint) ) Ensure the bezel is secure and does not move ) Ensure the bezel is grounded ) Ensure the bezel does not come into direct contact with the touchscreen SID 2007 Display Applications Conference Touchscreen Session 80

81 Surface Acoustic Wave Integration Considerations T Ensure there is sufficient room in the display to allow for the piezoelectric transducers and wires T Bezel to touchscreen sealing ) Select a gasket material that will not attenuate the SAW signal O A closed-cell polyolefin base foam is recommended ) Position the gasket material within the active area of the touchscreen O The gasket material should not contact the reflector array border pattern ) Bezel pressure exerted on the active area of the touchscreen may effect performance. SID 2007 Display Applications Conference Touchscreen Session 81

82 Infrared and Optical Integration Considerations T Infrared ) Mount the Infrared bezel assembly at an angle to prevent moisture or liquid collection ) Select good sealing material of the bezel to ensure there is no particulate buildup on the IR LEDs and phototransistors ) Recommended gasket materials are polyester, urethane and silicone T Optical ) Ensure there is sufficient room in the display to allow for the optical sensors and reflectors or LED arrays SID 2007 Display Applications Conference Touchscreen Session 82

83 Controller vs. Chipset Considerations T Chipset ) Design and qualification ) Design flexibility ) Support ) Supply chain management ) Lower cost ) Reduced space requirement ) Minimum order requirements T Controller board ) Reduced design and qualification time ) Higher cost ) Increased space requirement SID 2007 Display Applications Conference Touchscreen Session 83

84 Software T Touchscreen software drivers ) Windows 2000, XP, Vista, XPe, CE ) Linux support ) Custom T Control panel T Calibration T Utilities and diagnostic tool SID 2007 Display Applications Conference Touchscreen Session 84

85 Summary T Custom vs. standard product selection T Touch system considerations T Understand product specifications and integration requirements T Cost of ownership SID 2007 Display Applications Conference Touchscreen Session 85

86 Testing Plans & Methods (Bruce DeVisser) SID 2007 Display Applications Conference Touchscreen Session 86

87 Testing Plans & Methods 1 T Reference: The use-model you developed initially ) What form the user s interaction takes O Touch selection, tapping, dragging, writing, signature capture ) Methods of interaction O Bare or covered finger, stylus, other implement ) Use environment O Indoor, outdoor, temperature, humidity, air quality T Test model ) Two levels of test: Component and system ) Component (qualification) test O Test to manufacturer s specifications ) Unit or system test O Ensure proper overall operation after integration SID 2007 Display Applications Conference Touchscreen Session 87

88 Testing Plans & Methods 2 T Test parameters ) Normal use: Intended use-model ) Extreme condition: Not required, but nice to know in some cases O If it exceeds manufacturer s specs, results are not reliable T Test development ) Use all resources available O Experience: Yours and others in your organization O Vendors: Use supplied parameters and methods O Customer: Learn their expectations O Marketing: Product performance claims ) A comprehensive use-model combined with testing that covers all aspects of the technology will provide a reliable test tool SID 2007 Display Applications Conference Touchscreen Session 88

89 Testing Plans & Methods 3 T Test environment ) Lab testing versus unit or system testing O Lab is good for specific metrics related to components Use repeatable setups, vendor methods, industry standards (NIST, etc.) O More testing is needed if the vendor is less reliable ) Unit or system test O Replicate the user environment Lighting, weather, special conditions O Replicate user interactions, including error states ) Monitor O Input detection reliability O Performance degradation O Wear items O Initial field performance SID 2007 Display Applications Conference Touchscreen Session 89

90 Testing Plans & Methods 4 T Unit or system test examples by technology ) Resistive O Proper response to various actuating implements O Signature-capture / edge-scrolling performance O Surface wear (Taber wheel) ) Surface capacitive O Positive actuation, calibration ) Projected capacitive O Actuation distance above surface; multi-touch ) Surface acoustic wave O Sealed applications need to test for compression effects O Use OEM diagnostic tools to test and optimize performance ) Infrared O Use OEM diagnostic tools to determine beam width SID 2007 Display Applications Conference Touchscreen Session 90

91 Testing Plans & Methods 5 T Common test elements ) Function O Touch response O Touch accuracy ) Optical performance O Transmissivity O Reflectivity O Optical artifacts ) Wear items O Surface degradation SID 2007 Display Applications Conference Touchscreen Session 91

92 Purchasing Touch Components (Bruce DeVisser) SID 2007 Display Applications Conference Touchscreen Session 92

93 Purchasing Components 1 T Establish your needs ) Estimated annual usage (EAU) ) Schedule steps: Prototype, EVM, PVM, pilot, production units T Purchasing route who s buying your parts? ) OEM, integrator, VAD, CM/CEM T Purchasing locations ) Identify for each schedule step T Quantification ) Establish economic purchase quantities ) Identify needs for each phase and best purchasing route SID 2007 Display Applications Conference Touchscreen Session 93

94 Purchasing Components 2 T Common purchasing issues ) Which path? - OEM direct, distribution, or other O OEM direct availability depends on value, which varies by OEM O Distribution offers application support, stocking, lower financial bar, integration service, other related components, lower purchase mins. O Others offer specialized integration service and assembly ) Longevity of supply O Custom: Varies by OEM, but offers the best availability O Standard: Normally at the maker s discretion O Real world: Depends on level of business, negotiation ) Risk issues O Global supply: Production required for most firms O Product support: Anything can fail SID 2007 Display Applications Conference Touchscreen Session 94

95 Gotchas! (Bruce DeVisser) SID 2007 Display Applications Conference Touchscreen Session 95

96 Avoiding Mistakes T Know your user: Most critical item T Design is a team effort: ID, EE, ME, SW, support T Test for the unexpected: Your users certainly will! T Test the whole design: HW, SW, UI, ease of use T Test the system: Timely response to input is crucial T Set customer expectation level: No surprises T Warranty support vs. product life: Clear understanding T Serviceability: Has to be designed in at the start T Customer applications: Training and support are key T Expect the unexpected: Be prepared SID 2007 Display Applications Conference Touchscreen Session 96

97 Real-Life Gotchas T Toronto airport, winter blizzard, -31 C ) Multiple resistive failures from dropped scanners T University of New Mexico, magnetics lab ) Capacitive calibration failures T Factory automation, unwanted(!) ) Infrared interference T Radiology lab, loss of function ) SAW and sweating radiologists T Broken machines ) Failure to recognize input in a timely manner SID 2007 Display Applications Conference Touchscreen Session 97

98 Question & Answer Session #2 SID 2007 Display Applications Conference Touchscreen Session 98

99 SID 2007 Display Applications Conference Touchscreen Session 99

100 SID 2007 Display Applications Conference Touchscreen Session 100

101 Appendix (Information on some of the touch technologies that we didn t cover in the tutorial) SID 2007 Display Applications Conference Touchscreen Session 101

102 Optical Waveguide Infrared SID 2007 Display Applications Conference Touchscreen Session 102

103 Optical Waveguide IR 1 Illustration courtesy of RPO SID 2007 Display Applications Conference Touchscreen Session 103

104 Optical Waveguide IR 2 T Size range ) 2 to ~17 T Target applications ) Mobile devices T Market leaders ) RPO and partners (unannounced) SID 2007 Display Applications Conference Touchscreen Session 104

105 Force Sensing SID 2007 Display Applications Conference Touchscreen Session 105

106 Force Sensing 1 Touch-panel mounting frame Touch-panel (pink) Metal plate Strain gauge (4) Cut line for replacing inner metal piece with glass Slits in metal plate Opening for strain gauge mounting SID 2007 Display Applications Conference Touchscreen Session 106

107 Force Sensing 2 4 strain gauges supporting one touch panel Irregularly shaped, raised, textured, wooden touch surface Motor attached to and penetrating touch panel with printed speed control keys and push-pull control lever QSI s Demo Box from SID 2007 Glass-covered LCD integrated into touch panel with soft keys printed on back of glass Raised, marble touch surface with toggle switches penetrating touch panel Multi-page book with touchable metal pages Snap-dome keys attached to touch panel; removable padded and textured keys; speaker attached with holes through the touch panel. SID 2007 Display Applications Conference Touchscreen Session 107

108 Force Sensing 3 T Size range ) 8 to 42 T Target applications ) Architectural applications such as an elevator control panel made of steel, glass and stone containing floor buttons, an embedded LCD with soft keys and a speaker ) Possibly other applications requiring high durability T Market leaders ) QSI (sole supplier, for now) SID 2007 Display Applications Conference Touchscreen Session 108

109 In-Pixel Photos courtesy of TMD SID 2007 Display Applications Conference Touchscreen Session 109

110 In-Pixel 1 T Light-sensing ) Integration of an array of TFT optical sensors into the LCD s backplane O Like a camera without a lens O Works with finger, stylus, light-pen or laser pointer O Works as a scanner (e.g., for business cards) ) TMD was the first to do it (4/03) O Can auto-switch between shadow & reflection O No announced commercialization date ) Sharp announced the same concept 8/07 O No mention of working light range O Sampling now; mass production in 2Q08 Lightsensing TFT Pixel aperture Display TFT (Conceptual drawing) Sample captured image on 2.6 VGA (300 ppi) Image courtesy of Sharp SID 2007 Display Applications Conference Touchscreen Session 110

111 In-Pixel 2 T Capacitance-sensing ) Alternative in-pixel method uses display s ITO electrode structure as a self-capacitive sensor O Integritouch (a Swedish startup) seems to have fairly strong IP in this area (filed in 2003) Method: Periodically switch electrodes to connect to sensing circuit; drive electrode with square wave and measure change in rise time due to added capacitance of finger to ground O Samsung is experimenting with a variant approach Sensor array data obtained by placing an object on the LCD. Image courtesy of Samsung SID 2007 Display Applications Conference Touchscreen Session 111

112 In-Pixel 3 T Size range ) Light-sensing: 2 to 12 (Sharp s stated current limit) ) Capacitance-sensing: Unknown T Target applications ) Light-sensing: Mobile devices ) Capacitance-sensing: Unknown T Market leaders ) Light-sensing: TMD, Sharp, Planar & AUO ) Capacitance-sensing: Integritouch, Samsung SID 2007 Display Applications Conference Touchscreen Session 112

113 Frustrated Total Internal Reflection Illustration courtesy of Jeffrey Han, NYU SID 2007 Display Applications Conference Touchscreen Session 113

114 Frustrated Total Internal Reflection 1 Multiple touch points (Image taken without a diffuser) Illustrations courtesy of Jeffrey Han, NYU SID 2007 Display Applications Conference Touchscreen Session 114

115 Frustrated Total Internal Reflection 2 T Size range ) As described, ~32 and up T Target applications ) Interactive video walls and digital signage T Market leaders ) Perceptive Pixel (sole supplier, for now) SID 2007 Display Applications Conference Touchscreen Session 115

116 Laser Pointer Touch SID 2007 Display Applications Conference Touchscreen Session 116

117 Laser-Pointer Touch Illustration courtesy of Keytec SID 2007 Display Applications Conference Touchscreen Session 117