Filed under: multitouch — Harry van der Veen @ 12:34 am
Because of the fact that silicone rubber, rosco projection screen and acrylic are very static I wanted to point out that you shouldn’t saw or cut acrylic or polycarbonate in the same room where you store the rosco or the silicone rubber. The tiny acrylic particles stick to everywhere, so you will have a hard time getting rid of those particles in between your silicone rubber and the rosco. Ultra small particles that are a tenth of a millimeter create rather big bubbles on the projection screen.
If you are experimenting with making your own silicone rubber compliant surface overlays and there are dust particles in them, I suggest that you put a piece of tracing paper on top of the silicone rubber, before you apply the Rosco. Little particles in the Silicone are less noticeable with the tracing paper on top. Now you can also place the Rosco with the none shiny side down, so that the overall look is better. Also your blobs are sharper this way.
Filed under: multitouch — Harry van der Veen @ 6:41 pm
After building a lot of multi-touch prototypes with normal IR leds, one of my co researchers, Peter Bomark, did some prototyping with Surface mounted leds. Eventhough this approach requires more knowledge of electronics, we prefer the use of this method above normal IR leds, because of the efficient spacing and the clear and professional look of it. Mounting them is the biggest gain and wiring is less hassle. The leds we used are the SFH421.
Filed under: multitouch — Harry van der Veen @ 7:49 am
I wanted to give 2 tips regarding handling projection screen and Rosco in particular. I don’t know if this applies to other projection screen materials, but because we have experimented with Rosco Grey a lot, I figured I should post it here. For some people it might be common sense, but I’m sure not everybody uses projection screen on a regular bases.
The 2 tips I wanted to point out:
* Never fold your Rosco. Roll it instead. Because when you fold it, it will leave marks, that you can’t remove. It will actually damage the material.
* Be careful with what kind of material you clean your Rosco with, if its dirty. For example, if you clean it with Aceton, it will leave very tiny scratches. It doesn’t really destroy the projection, but still, it’s not a nice view, when your screen is off that you see these imperfections.
Filed under: multitouch — Harry van der Veen @ 1:11 am
Basically what also would be an option is to have a microphone on the side of the screen, or use the one integrated in your laptop for example, to tap on, to register the tap. If the microphone sort of picks up this tap, you could couple a specific task to it.
Filed under: multitouch — Harry van der Veen @ 2:54 pm
I have found out that covering your silicone rubber sheets while curing gives a better end result. This way small dust particles in the air can’t settle and cure into the surface of the silicone rubber. Usually these small particles cure into the silicone rubber and therefore create little artifacts in the surface. By covering the silicone rubber while curing you have a bigger chance of creating a better sheet.