Hardware & Technical Can a traditional tablet screen be made to sense light?

[Globusdiablo]

Hey techies!

I've been wondering: A tablet can emit light, but can it or can it be made to register light? Through software and without altering the tablet itself.

Thanks in advance and fly safe.

 

[Asp Explorer]

Some of them have ambient light sensors. Some have cameras. You could query either for light levels, either direct sensor data, or take a picture and see if it's mostly black.

 

[Globusdiablo]

Some of them have ambient light sensors. Some have cameras. You could query either for light levels, either direct sensor data, or take a picture and see if it's mostly black.

Cheers Asp. Yeah, but my query is mainly whether the touch screen itself is/could be capable of emitting and registering light sources. Not just touch.

 

[Asp Explorer]

Years ago I remember reading a paper that LED's acted as photodiodes at specific frequencies. All the LED's that make up your screen pixels will put out current when they receive light. Unfortunately, the voltage is going to be tiny, and the current will be blocked at least at the multiplexor or rasterizer.

What are you trying to do? You can get photodiode matrices with serial ports you could overlay on the screen if you wanted to know if a specific area was illuminated, but that would be a real cludge!