Henri Legentil Thomas Zubeli Tactile devices Henri Legentil Thomas Zubeli

Outline Introduction Definition History Digital technologies: Resistive Capacitive Surface acoustic Strain gauge Optical imaging Dispersive signal Acoustic pulse recognition Conclusion

Introduction Why this topic? What is included in “tactile devices”? - At first, quite a new technology even if we’ll see that not that new. - Get out of the pure “computer domain” (we’ll see applications) Basically, everything that can be controlled by the touch. But we are gonna give a more precise definition... -> (next slide)

Outline Introduction Definition History Digital technologies: Resistive Capacitive Surface acoustic Strain gauge Optical imaging Dispersive signal Acoustic pulse recognition Conclusion

Definition “Device fitted with a system which enables to execute actions by finger-pointing areas on a delimited zone.” General structure: Sensors Controller Software Structure: Sensors Controller: always an electronic card linked by a flexible cable Software: most of the time a computer

Outline Introduction Definition History Digital technologies: Resistive Capacitive Surface acoustic Strain gauge Optical imaging Dispersive signal Acoustic pulse recognition Conclusion

History 1960s: Academic & corporate researches 1971: 1st “touch sensor” by Sam Hurst (founder of Elographics): “Elograph” 1974: 1st transparent touch screen 1983: 1st commercial touch screen computer HP-150 1970s-1980s: all significant technologies Emerged from academic and corporate research labs: second half of the 1960s. 1971: first "touch sensor" developed by Dr Sam Hurst, founder of Elographics, company that has made most of the discovers and improvements in this domain. By this time, he was an instructor at the University of Kentucky. The "Elograph" was a screen but not transparent. However, it was a significant milestone in touch screen technology. 1974: first true touch screen incorporating a transparent surface came on the scene (still Sam Hurst) 1983: The HP-150: world's earliest commercial touchscreen computer. Virtually all of the significant touchscreen technology were developed during the 1970s and 1980s. columbia.edu

Outline Introduction Definition History Digital technologies: Resistive Capacitive Surface acoustic Strain gauge Optical imaging Dispersive signal Acoustic pulse recognition Conclusion

Resistive Technical explanation Pros & cons Applications

Resistive – Technical explanation Composition of a resistive touch screen: Composition : Two flexible sheets coated with a resistive material and separated by an air gap and microdots. Contact  2 sheets pressed record the location Inconvenient of this method ? (next slide)

Resistive – Technical explanation More detailed view of a resistive device: 4 reflecting surfaces, identified as S1 through S4 S1 and S4 each reflect 4% of the incident light S2 and S3 each reflect around 5% of the incident light S5 reflects about 2% of the incident light Total reflectivity is around 20 %  It's clear that an LCD with an untreated resistive touch screen is unreadable in sunlight

Resistive – Pros & Cons Pros: Cons: Cheap Durable Bad clarity According to you, what are the devices perfectly adapted to that technology ?

Resistive – Applications Nintendo DS PDA Mobile Phone (i.e. HTC) GPS Touchpad http://video.google.com/videosearch?q=Nintendo%20DS%20Touchscreen&ie=UTF-8&oe=utf-8&rls=org.mozilla:fr:official&client=firefox-a&um=1&sa=N&tab=wv#q=demo%20Nintendo%20DS%20Touchscreen&emb=0

Outline Introduction Definition History Digital technologies: Resistive Capacitive Surface acoustic Strain gauge Optical imaging Dispersive signal Acoustic pulse recognition Conclusion Capacitif : iphone

Capacitive Technical explanation Pros & cons Applications Capacitif : iphone

Capacitive – Technical explanation Composition of capacitive touch screen: A capacitive touch screen consists of a glass panel with a capacitive (charge storing) material coating its surface. Describe the picture above

Capacitive – Technical explanation The screen Capacitive touch screens have front and back protective glass providing optical and strength enhancement options

Capacitive – Technical explanation The screen Its middle layer consists of a laminated sensor grid of micro-fine wires, and optical enhancement options

Capacitive – Technical explanation The screen During a touch, capacitance forms between the finger and the sensor grid. The embedded serial controller in the touchscreen calculates touch location coordinates and transmits them to the computer for processing. Do you have an idea of the pros & cons ?

Capacitive – Pros & Cons High touch resolution High image clarity Not affected by dirt, grease, moisture Cons Must be touched by finger, will not work with any non-conductive input + Thick glass  image clarity + Voltage drop  Not influenced by non conductive materials (not by dirt, grease and moisture) Voltage drop  Won’t work with gloves for instance

Capacitive – Application iPhone Ticketing machine Thick glass Almost unbreakable (in case of vandalism) Ticketing machine : http://www.gettyimages.com/search/detail.aspx?id=834-27&esource=feed_google_video Some research showed that women prefer HTC to Mac’s mobile phones because iPhone can’t be used with fingernails

Outline Introduction Definition History Digital technologies: Resistive Capacitive Surface acoustic Strain gauge Optical imaging Dispersive signal Acoustic pulse recognition Conclusion

Surface acoustic Technical explanation Pros & cons Applications Surface acoustic wave discovered in 1885 by Lord Rayleigh

Surface acoustic – Technical explanation Wave through an elastic material Generator, resistance measure When the panel is touched, a portion of the wave is absorbed change in the ultrasonic waves => position Send information to controller Wikipedia

Surface acoustic – Pros & Cons Usable with everything Perfect image Cons Fragile Usable with everything (finger, glove, stylus)(avoid sharp objects) Perfect image (100% transmission: ideal for detailed graphics) Can be easily damaged by outside elements (dirt, scratch)

Surface acoustic – Application Graphic design Only there because only place where fragile not important and precision needed

Outline Introduction Definition History Digital technologies: Resistive Capacitive Surface acoustic Strain gauge Optical imaging Dispersive signal Acoustic pulse recognition Conclusion

Strain gauge Technical explanation Pros & cons Applications Strain gauge: Invented by Edward E. Simmons and Arthur C. Ruge in 1938 Once again, concept originally not used on screens. Other uses: temperature (distortion with heat), mechanical (house starts to collapse)

Strain gauge – Technical explanation Screen spring-mounted Flexible resistance The screen is spring-mounted on the four corners CLIC! Each gauge: flexible backing supports a metallic wire. strain gauges => determine deflection (movement) when the screen is touched. Force on 4 gauges => compute position of object EXAMPLE: table (4 feet) Wikipedia

Strain gauge – Pros & Cons Z-axis measurement Resistant Movement Usable with everything Cons Accuracy Z-axis: drawing (Photoshop): pen wide or thin Resistant: gauge durable

Strain gauge – Applications Exposed public systems Ticket-machines (Resistant to vandalism)

Outline Introduction Definition History Digital technologies: Resistive Capacitive Surface acoustic Strain gauge Optical imaging Dispersive signal Acoustic pulse recognition Conclusion

Optical imaging Technical explanation Pros & cons Applications

Optical imaging – Technical explanation Composition of optical imaging touch screen: A relatively-modern development in touchscreen technology The light is emitted in a plane across the surface of the screen At the heart of the system is a printed circuit controller board The optical sensors track the movement of any object close to the surface by detecting the interruption of an infra-red light source

Optical imaging – Technical explanation Composition of optical imaging touch screen: A relatively-modern development in touchscreen technology The light is emitted in a plane across the surface of the screen At the heart of the system is a printed circuit controller board The optical sensors track the movement of any object close to the surface by detecting the interruption of an infra-red light source

Optical imaging – Pros & Cons No pressure is required Provides multi-touch capability Plug-and-play Cons Needs to be calibrate

Optical imaging – Applications Military applications Military because of its toughness And many other kinds of applications

Outline Introduction Definition History Digital technologies: Resistive Capacitive Surface acoustic Strain gauge Optical imaging Dispersive signal Acoustic pulse recognition Conclusion

Dispersive signal Technical explanation Pros & cons Applications

Dispersive signal – Technical explanation Sensors corners/backside of glass Glass composed by substrate sensitive to vibration CLIC: Generate vibrational energy CLIC: Sensors get signal Ask audience problem??? -> VIDEO CLIC: Advanced dispersion adjustment algorithms are then applied to the data CLIC: Subtract the reflected wave 3M.co.uk

Dispersive signal – Pros & Cons Accurate Object resting on screen ignored Resistant Usable with everything Cons A bit slow No movement Processing allow good accuracy As palm of hand/object doesn’t generate vibrational energy => not detected => can put palm of hand on the screen Ignores scratches (doesn’t generate energy) Needs a lot of processing When slide finger, not enough energy (vibration) detected

Dispersive signal – Applications Exposed public systems Long use purpose Resistant Long use: Possibility to put palm of hand on screen (Gorilla arm)

Outline Introduction Definition History Digital technologies: Resistive Capacitive Surface acoustic Strain gauge Optical imaging Dispersive signal Acoustic pulse recognition Conclusion

Acoustic pulse recognition (APR) Technical explanation Pros & cons Applications

APR – Technical explanation Composition of a APR screen: Acoustic Pulse Recognition (APR) touchscreens use a completely new and unique way of sensing touches on a display It’s only of a glass overlay mounted in front of the display, together with a small electronic controller board

APR – Technical explanation Composition of a APR screen: 1 - This system uses four piezoelectric transducers 2 - The transducers are mounted on two diagonally opposite corners out of the visible area and connected via a flex cable to a controller card 3 - Transducers turn the mechanical energy of a touch (vibration) into an electronic signal. 3 - This signal is then converted into an audio file, and then compared to preexisting audio profile for every position on the screen

APR – Pros & Cons Pros Cons Plug-and-play Works with gloves, fingernails Resistant to water Cons Drag-and-drop doesn’t always work well Cons : Since it uses the vibration creates by a pressure on the screen, the drag-and-drop won’t work

APR – Application Restaurants Cons : Since it uses the vibration creates by a pressure on the screen, the drag-and-drop won’t work ELO demo : http://www.youtube.com/watch?v=alz6kbkXqgk (drag-and-drop) works well on video 

Outline Introduction Definition History Digital technologies: Resistive Capacitive Surface acoustic Strain gauge Optical imaging Dispersive signal Acoustic pulse recognition Conclusion

Conclusion Gorilla arm State-of-art Market projection Main issue: Gorilla arm: human not used to hold arm in front of head -> Gorilla position Working on multitouch: more interactive, multi-users (collaborative work) With the influence of the multitouch interactivity, the touchscreen market for mobile devices is projected to produce US$5 billion in 2009.

Thank you! Questions? Main issue: Gorilla arm: human not used to hold arm in front of head -> Gorilla position Working on multitouch: more interactive, multi-users (collaborative work) With the influence of the multitouch interactivity, the touchscreen market for mobile devices is projected to produce US$5 billion in 2009.