New And Improved LCDs

Ender42 writes "Princeton scientists have created a variety of light-emitting materials that could greatly accelerate the development of flat-panel computer screens and other compact video displays. The discovery, a feat of engineering materials at the level of quantum mechanics, also may yield insights into the basic properties of light-emitting substances. " Practically speaking this means cheaper, higher res, lower power LCD displays. "

Comments

Correction

[Silicon_Knight]

If you read the article, you can see that this is *NOT* for LCD use. It's an L*E*D display.

LCD displays work by having an optically active (chiral) organic molecule layer (called the liquid crystal) sandwiched bewteeen 2 layers of polarizing filters, set at 90 degrees angle. When a current is applied the orientation of the liquid crystal layer changes, and the light's polarization plane doesn't get rotated the 90 degrees to clear the second filter. (Thus appearing to be dark). Take away the voltage, the crystals returns to ground state, plane polarized light is rotated 90 degrees, and it clears the second filter and appears to be transparent. This is how LCD displays on calculators work; color displays built on this principle and add a backlight on the back (ie, laptop) and by controlling the amount of light that passes thru for each pixel, generates the different colors. Note that the light emmision criteria has nothing to do with the liquid crystals; that's why you can't read your calculator in a dark room, and that's why palm devices have a backlight. Another cool thing to try is to take a polarizing sunglasses and hold it between your eye and the laptop screen and rotate it slowly. The display will get darker (at 90 deg) and brighter again (at a full 180 deg).

Now that we have amused ourselves with LCD technology, let's take a look at what these guys at Princeton actually did:

They found a new material that can be used in light emitting diodes. LEDs are used for indicator lights on the electronics that we all love. Traditionally, LED displays for flat panel applications are problematic for 2 reasons:

A: Making the pixels small enough, on a large display.
B: Finding a materials for blue LEDs.

The problem with blue LEDs was solved a few years back, but as far as I know A is still a limitation. If you ever look at those big "SonyTron" LED displays in stadiums, up close the pixels are about the size of your THUMB.

In order for this to suceed, there needs to be a good commercial process to apply the OLED material onto an (ideally) plastic substrate. Plastic substrates are really the way to go because they are less prone to breakage and don't require massive retooling. Hopefully, since the material is organic in nature, incorporating it onto plastic won't be such a difficult idea.

-=- Terence