During the summer, I was building my multitouch table out of an LCD screen. I took the back off the lcd screen (backlight and all) so I could place a camera below it to see my hand as I touched the LCD (LCD screens are transparent ). The problem was that the screen does not give off its own light so I had to make a light below (and below the camera 19in away)to shine through the LCD, and illuminate it.
But… Because the LCD is clear, when you looked through the screen you would see the individual LED lights I used to light it up causing huge hot spots. This was a problem. Normally I would use a diffuser to fix this, but I needed the camera to have a clear view of the back of the LCD so I had to figure something else out. The main issue was that with a normal LCD when the screen is white, it is actually almost completely clear, so you where just seeing the backlight. In mine, you see the LED array, and the camera, and everything else in there. So I took some vellum and made a cone diffuser that went from the LCD screen to the camera. This allowed the LCD to have a complete diffused back light and allowed the camera to have a clear view as well.
Below the Diffuser I put my array of 192 LEDs. Works great, but it’s not as bright as I wanted. I just have to upgrade the lights. (they are already on their way.) I just have to wait till after my break (going to visit family) to work on it.
Back to work on FoodE <– Final for my service design class