Back projection 56 inch multitouch television.

Step 2: Material needed

Material needed

This is the component I use now in my system. You can use different gear and get same or better results.

-Computer core2 recommended
-Projector 550$ on ebay
-Webcam 55$ on tigerdirect
-Special lens 25$
-IR Filter 25$
-36 x 48 inch Plexiglas 1/2 inch 150$
-36 x 48 Rosco Gray Rear-Projection Screen 30$
-168 Osram SFH485 880nm IR LEDs 115$
-Wire and resistors 20$
-Silicone 6$
-Toluene 20$
-Protective foil Different from mine--- Seems similar 30$
-Mirrors
-Tapes
-Glue
-Black paint
-Mdf, hdf or plywood sheets
-Front speaker fabric 40$
-Many different tools
-screws
-wood finishing product
-paint filter
-paint can
-Sound system 115$

Comments

[GoldCannon]

is there such thing as a projector lens that can project a fully proportional rectangular image when mounted at the side of the screen, not in the center? If I were to build a multi touch desk and need at least some space for my legs under the table, i would need to put the projector somewhere at the opposite side with a special lens, but i still want the image to reach to the edges of the table. Would this be possible?

[guunhan]

I believe the setup your looking for is a telecentric lens.

[Hoaxe]

what you need is an "optical engineer" or an "optical designer", that sort of thing, to help you figure out how to build this lens of yours. I have never seen anything that could do that, but hit me up if you do. there's probably an e-mail in my profile or something. you could also try pushing the projector back and tilting forward and then just use a regular Isosceles trapezoid regulating feature seen on most projectors to fix the picture. a last try is to project the image from the top. the picture would appear on your hands when on it but other than that, i don't see why not.

[jantunes91]

Hi. I'm doing a project similar to this for school and I can't seem to understand the purpose of the Special Lens and the IR Filter. I've seen other tutorials where these items are not required to modify the webcam. I you can light me up on this, I'll be very grateful. Thanks in advance, jantunes

[Hoaxe]

I don't get what the [silicone = seal and caulk] is. is it even transparent? i didn;t even know seal and caulk was made of silicon...

could you provide more details on that?