Skip to content

June 14, 2009


Multi-Touch Table – Planning Begins

With the decision to try and build a multi-touch table comes a lot of planning.  Anyone who thinks they can just jump in feet first and be successful will probably find themselves quickly disappointed.  It doesn’t mean they won’t be successful, just that the journey will probably be much harder than they anticipated.

With that in mind, I’m taking a bit of time to work out some details before making any major purchases.  The first decision I needed to make is what kind of technology I’m going to use as the basis of the table.  There are several ways to build a multi-touch surface, all of which can be found over at the NUI Group website.  For my table I am choosing LLP, or Laser Light Plane, because of it’s ease of construction (relatively speaking) and it’s ability to provide fast and precise finger tracking.

The parts list for an LLP table is fairly short:

  • Lasers – most commonly 780nm 5-25mW
  • Surface material – acrylic, Lexan, glass
  • Projection material – sits behind the surface material and allows an image to be displayed
  • ‘Blob’ detection camera – this device detects the actual “touches” by seeing the scattered IR light from the lasers
  • Projector – fairly self-explanatory
  • Mirrors – used to extend the throw length of the projector, more on this later…
  • Framing and other construction materials – All the junk to tie it together.  I’m hoping to use T-slot aluminum extrusions for the core of this.
  • A computer to tie it all together and to run the apps!

Some of these items are no-brainers – the lasers for one.  The sooner I have those the sooner I can start fabricating mounts for them, figuring out how to power them, and so on.  Others, such as the projector, require some careful consideration.  Following entries will detail the selection process for these components.  Signing off for now.


Read more from Multi-Touch

Share your thoughts, post a comment.


Note: HTML is allowed. Your email address will never be published.

Subscribe to comments