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Light Emitting Pictures On Standard Inkjet Printer
CrashRide writes: "This story on FOX states that UofA scientists have discovered a way to print light-emitting pictures on thin sheets of plastic using a standard inkjet printer. Fold up pocket monitors?" The article says that these scientists have produced "OLEDs of simple bands of light, a scorpion, the University of Arizona logo and even photographs of themselves."
There is a better story on the UA newspaper. And here is the link to research department. Not much here yet except for an animation.
This is just a poster that glows -- it's a static picture that glows using a low amount of electricity. Unless you're running Windows, and all you need to display is the same bsod, you'll need a more "dynamic" display :).
If you can print conducting traces, you could set up a grid pattern of traces around pixels that would let you selectively activate pixels, much as you do in a passive-matrix LED. At any given time, one horizontal line (say) would be ground, and the rest would be at Vdd. Vertical lines would be driven or not driven depending on whether you want pixels in the active line on or off. If these printed pixels really are OLEDs - diodes - then you won't have to worry about the other horizontal traces shorting across the vertical lines.
I'm sure there are a number of ways of printing conducting traces with ink. Even a high-resistance trace could be electroplated after printing with thicker metal.
The only question is whether a) the type of OLEDs printed with this technology are really diodes, passing current only in one direction, and 2) whether instantaneous current can be high enough to give an acceptable _average_ current (and brightness) per row over the whole scanning cycle. A row turned on one thousandth of the time needs to be a thousand times as bright when it's on.
Other methods of addressing pixels in a display are of course possible. This is just one of the easiest (not necessarily best).
Not trusting the headline whores at fox news, I did a little searching on google and found this article published in June of 2000. It has a better review of the actually technology from a pure science point of view, rather than the "marketing press release as if it were a product" garbage that was posted.
"Get them before they get....
When I was a graduate student at UCLA in 1998, I heard of Professor their that already patented the process for using ink-jet printing techology for creating Organic LED devices. The original paper is: S.C. Chang, J. Bharathan, and Y. Yang; "Dual-color polymer LEDs processed by hybrid inkjet printing technology", Appl. Phys. Lett., 73, 2561, (1998). If you want to know more about this, visit Dr Yang's website at http://www.seas.ucla.edu/ms/faculty1/yang-yang.htm l.