Multi-touch Technologies; Hardware and Optical Tracking Techniques

Lecture 2 : Multi-touch technologies: Hardware and optical techniques

By Jazmi Jamal

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Outline

Introduction to multi-touch technologies

Multi-touch hardware tracking technique

Hardware: Display screen, input sensor, & computer processor.

Optical techniques: DI, FTIR, LLP, DSI, LED-LP

Multi-touch refers to a touch system's ability to simultaneously detect and resolve a minimum of 3 or more touch points. Multi-touch is considered by many to become a widely-used interface mainly because of the speed, efficiency and intuitiveness of the technology.

History of multi-touch

1980 2008

First MT display Toronto University

HP 150 worlds first touchscreen PC

Simon – first smartphone with touchscreen

Mitsubishi : Diamond Touch

Uni of Toronto; Multi-finger, hand, UI

Jeff Han: Budget MT

Foundation NUI group

Apple: iPhone

Microsoft Surface

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For more info: http://www.billbuxton.com/multitouchOverview.html

igital computer capable of being reprogrammed to solve a full range of computing problems

HP 150

HP Touch Computer, 1983http://www.youtube.com/watch?v=X-THdG5gVTw


Simon: 1st smartphone with touchscreen

IBM, 1992No physical button to dial.


Diamond Touch

Mitsubishi, 2001Projection on coffee table


Budget Multi-touch

Jeff Han @ TEDTalk, 2006http://www.ted.com/talks/jeff_han_demos_his_breakthrough_touchscreen.html


tBeta / CCV

NUI Groups, 2006Open source multi-touch

iPhone

Apple, 2007Multi-touch smartphone

Microsoft Surface

Microsoft, 2008Multi-touch interface tabletop

Enough History!

Multi-touch Hardware Technology

Multi-Touch Hardware Tech

Touch Technology

Optical (this is my topic)

Infrared (IR)

Bending Wave

Projected Capacitive

Resistive

Surface Acoustic Wave (SAW)

Surface Capacitive

Established a group of 2 or 3 then discuss and present the existing touch technologies.

Multi-Touch Hardware Tech

The criterions

What is it ?

How is the technology function ?

How much is the price ?

Sample product using the technology

What is your comment regarding this technology ?

Please apply multimedia materials in performing the presentation.

Provide evidence and reference regarding the content.

These are some questions require to be answered in the presentation

Presentation time: 10 mins

Optical (for example)

What ?

Optical or light sensing MT was based on optical sensor (normally camera).

nuicode.com/attachments/.../Multi-Touch_Technologies_v1.01.pdf


Function

The technique consists of optical sensor, infrared light source, and display.



Price

Low cost

Range from RM 200-500 excluding computer and display projector.

http://www.instructables.com/id/How-To-Build-An-Optical-Multitouch-Setup-FTIR-Re/


Sample product

Prudential MT coffee table

http://www.youtube.com/watch?v=Yn_j8s4SWZM


Comment

-The cheapest technology setup, because most of the equipments are available in the market.

- Hard to setup, requires lot of hassle.

20 minutes. Start from NOW!

OK, done presentation, NEXT!

Optical hardware time!

Optical Hardware

Optical technology hardware consists of:

Infrared light sources & infrared cameras

Display : Projector and surface.

Infrared Light Sources

Infrared is a portion of the light spectrum that lies just beyond what can be seen by the human eye.

IR light is mainly used to distinguish between a visual image on the touch surface and the finger(s) being tracked.

Infrared Light SourcesIR Light Sources:

Single LED LED illuminator LED Ribbon IR Laser

Infrared Camera

Commercial Infrared camera : Security cam, camcorder, nightvision, spycam.

Normal Webcam camera with modification (take out IR filter inside the camera).

Camera specs need to be considered:

Resolution, Frame rate, Interface, Lens type, Bandpass filter

Projector (Display)

Display visual feedback on table.

Display versatile size.

2 types of projectors: DLP and LCD

Important: Brightness (ANSI Lumens), Throw Distance, Aspect Ratio

Projection surface (Display)

Light diffuser: device that diffuses or spreads out or scatters light.

Semi-transparent surface or transparent surface that can capture light.

For instance:

http://www.da-lite.com/products/product.php?cID=10&pID=335

Need a break ?

Continue to Optical Technique

Optical Techniques

Composition of optical-based multi touch technology in making it function.

Establish a group of 3 or 4 members. Discuss and present about the existing optical techniques

Diffused Illumination (DI)

Frustrated Total Internal Reflection (FTIR)

Laser Light Plane (LLP)

Diffused Surface Illumination (DSI)

LED Light Plane (LED-LP)

Optical Techniques

Please apply multimedia materials in performing the presentation.

Provide evidence and reference regarding the content.

These are some questions require to be answered in the presentation

Presentation time: 15 mins

The questions

What is the ___ technique ?

What equipments is required ?

How to setup ?

What are pros n cons of the technique ?

What ?

IR light is shined at the screen from below the touch surface

Object touches the surface it reflects more light than the diffuser in the background

The extra light is sensed by a camera.

http://wiki.nuigroup.com/Diffused_Illumination

Diffused Illuminator

http://wiki.nuigroup.com/Diffused_Illumination

DI Equipments

Equipment Product/Model Comments

IR CameraPS3 ToyCam (Modified)

Remove filter and replace with IR filter. Extend lens.

LED Illuminator TZOR - 001 Add light diffuser to soften the light

Projector BenQ MP512-STDLP short throw projector. 1300 ANSI Lumen

Projection SurfaceAcrylic glass with frost laminate

20-30% transparency

Optical Techniques

DI: Advantages & Disadvantages

Advantages Disadvantages

Not much hassle; just a diffuser/projection surface on bottom.

Difficult to get even illumination

Can use any transparent material like glass (not just acrylic).

Blobs have lower contrast

Can track objects, fingers, visual markers and hovering.

Greater chance of false blobs

Enclosed box is required


OK YOUR TURN! 20 mins

Finish! Q&A session

Multi-touch Technologies; Hardware and Optical Tracking Techniques

Education

Transcript of Multi-touch Technologies; Hardware and Optical Tracking Techniques