Revision as of 07:02, 31 May 2007

Overview

A touchscreen interface that allows for multiple points of contact for uniquely manipulating objects and information on screen.

Status

Planning

Design concepts

• Ideally would be linked to screen resolution rather than physical size making it highly scalable.
• A transparent layer capable of being laid over any existing screen, projected or otherwise.
• System software would control generic interaction techniques that would work with all existing applications as well as newly developed ones.

Existing designs

• Jeff Han's: Acrylic sheet backed with a difuser(a solid surface to project on) and lined along the side with LEDs in a mobile frame capable of holding the projector and camera below the screen. A small solid lip surrounds the edge of the acrylic to prevent the light from escaping at acute angles causing the light to be reflected internally along the full length of the sheet. Placing a finger or other object on the surface causes light to scatter in a mostly perpendicular direction to the sheet making a bright spot on the difuser below which the camera then picks up and registers as a manipulation point. It is unknown that type LEDs Jeff Han uses, but other examples use infrared LEDs, which most digital cameras/webcams are capable of picking up. This is likely the cheapest way to produce large multitouch screens.

Preliminary notes

Working off the Jeff Han design, that is to say acrylic sheet with IR LEDs, projector from underneath, and IR sensitive camera, I'm going to see how shallow I can get the table by use of a concave mirror. The concave mirror should make the image larger, thereby decreasing the distance the projector needs to be from the projection surface, but will flip this image(easily corrected on the projector itself).

Brimstone, I seriously need a blog like yours :)

Progress

• 05/13/2007: Obtained a dinner plate sized convex mirror. Testing on focal length distance and size increase can begin.
  • This type of mirror doesn't look like it's going to work out. Too much distortion around the edges. --strages 06:34, 31 May 2007 (CDT)
• 05/31/2007: Given the release of Microsoft's Surface it got me thinking. I can make a better multitouch surface....with blackjack and hookers. Haven't quite figured out how I'm going to do the hookers part just yet, but managed to come up with a reasonable enough blackjack solution(see notes above). Came up with an alternated design based on the desks we have at work after a discussion with a coworker trying to explain the flexibility of having a large multitouch surface(again see notes above). Also came up with an idea for doscument "scanning" based on what Nykodemus has been doing with his book "scanning" rig, which strangely isn't on the wiki(ahem!).
  • I'll be needing a basic physics engine, preferably one that runs on top of all the applications as opposed to a per application basis, that handles "throwing" of windows and basic collision between windows.