Thickness Problem

Today, I spent a good deal of time trying to think about ways to make our touchscreen a lot thinner. So after being bugged by Keegan to start posting, here is my stream of conscience recap of what I looked at:

To start, one of the biggest problems with space is that the camera needs to be so far away to completely see all of the touch-able surface. As it stands right now, our screen is a 19" diagonal LCD which equals a width of about 17". So using some basic math we have:


So we need our camera to be about a foot away from the LCD plus the ~3" for the size of the camera and the length of material to attach it to our container.

My first thought was to look into cameras. I wiki'ed a bunch about how the CCD and CMOS parts of digital cameras work. So this lead me to wonder if they made large-scale but low resolution CCD plates that we could stick directly under LCD. No luck there however. The biggest sensor I could find for sale was a little over an inch wide and was very expensive ( $_$ ).

Next, I started looking into whether or not we could find/make a capacitive sheet that reacted to infrared light. So this lead to a bunch of wiki'ing and I found a good page about transparent films that are being used today. I then contacted a place that makes conductive coatings but I have yet to receive a response.

My next thought was looking into whether or not there was some extreme wide angle lenses that we could attach to the camera so that we could move the camera much closer and save space. However, all I could find was a bunch of thousand dollar lenses that attached to thousand dollar cameras. Similarly, I looked into whether or not there is some kind of special shaped and made glass that could bend light into a very small area, sort of like how mirrors for stores are used so that storekeepers can see shoplifters up and down a long isle or how security cameras have warped lenses to see a whole area. No luck.

So then I stated to consider if it would be easier to find a non-transparent film (because maybe that is a more reasonable request?) and then find a special kind of diffuser that would allow IR light to pass through. Or if we could get a diffuser that allowed IR light to pass, we could close up the diffuser, LCD, and acrylic in a separate container and then conceal cameras elsewhere in the design.

And now I am brain dead...

Update - 8/4/10 4:04 PM

Keegan has found some acrylic called Endlighten (c) that apparently works as both a IR diffuser and backlight. Check it out!