LCD Screen With Embedded Optical Sensors

dk3nn3dy writes "Sharp has developed a LCD display with optical sensors built into the displays pixels, without requiring a touch-sensitive film to be bonded on top of the regular screen. The optical sensor is similar to that used in scanners, allowing for notes or business cards to be scanned by the screen itself. As the optical recognition technology is built into the pixels it also simplifies tactile recognition based on simultaneously touching multiple points. Future uses include fingerprint authentication on the screen of your mobile phone or PDA, or iPhone style touch recognition. Volume production will start next spring."

Re:Is it true?

[JaWiB]

http://www.engadget.com/2006/04/26/apple-patent-em beds-thousands-of-cameras-among-lcd-pixels/ [engadget.com] I dunno, sounds like this is just for touchscreen applications, but Apple was focusing on using the screen as a webcam. What the difference between "optical sensors" and "thousands of cameras" is I do not know.

All OLED screens can do this already

[maokh]

All LEDs inversely function as light detectors, even while emitting light. All that is really needed is a display controller that is designed to detect this reverse current flow. It would be interesting to see such an application. The only thing I have seen so far is a traditional LED matrix that works like a touch screen to turn each individual LED on and off.

Don't believe me? Here is a primer:

http://mvh.sr.unh.edu/mvhinvestigations/light_inve stigations.htm [unh.edu]

LED do that without sensors

[Anonymous Coward]

LED do that without sensors so OLED might do it as well.
It is known that the electric resistence of a LED is lower when it is lit up externally so if you put something bright near it, the resistence lowers because it receives its own light back. I wonder if it works for organic leds too, so if you can sense the resistence of every pixel on a OLED display you can know if there is something bright in front of each pixel. The image would be B/W I guess but I think it must be cheap and enough sensitive to make multi-touch displays.
White hand palms in colour people might mean evolution thinks further than we do. ;)