PORTLAND, Ore. A possible successor to the CRT, LCD and even the organic LED is being readied, according to a MEMS film developer.
Uni-Pixel, Inc. (Woodlands, Texas) recently announced volume production of its first thin-film products. Dubbed "Opcuity," the films are used in time-multiplexed optical shutter (TMOS) displays that can be up to 10 times brighter and 60 percent cheaper to manufacture than LCDs. The films also can be fabricated on the same manufacturing lines as LCDs.
"One of the beauties of our manufacturing process is that it subtracts from existing LCD lines--you just need to remove some equipment that is no longer needed," said Uni-Pixel's CFO James Tassone. "Since we use no red, green and blue sub-pixels, our process is less demanding, requiring only one-third as many thin-film transistors.
"In fact, we can use LCD manufacturing lines that are aging and due to be retired; instead of scraping an aging LCD line, you can retrofit it to make our advanced TMOS displays," Tassone claimed.
TMOS displays use only a single layer of MEMS film between the bottom ("mother") glass and the top glass sheet in an existing LCD structure. By contrast, LCDs have five different layers between the bottom and top glass, including polarizers and color filters that reduce light emissions. As a consequence, the single layer used with TMOS produces displays that are much brighter than LCDs produced on the same line.
Instead of using sub-pixels for red, blue and green, each pixel in Uni-Pixel's MEMS film is uniform, deriving its color by time-mutiplexing the red, green and blue light from side-mounted LEDs that inject light into the bottom glass layer. The scheme acts as a light guide.
Instead of a white backlight to illuminate RGB subpixels, Uni-Pixel's approach routes light from side-mounted LEDs onto the same pixel, with the Opcuity film acting as an optical shutter.
Applying a voltage to a TFT causes the Opcuity film to deform downward, coming into contact with the bottom glass, routing light from LEDs up to a particular pixel. By time-multiplexing in synchronization with the blinking red, blue and green side-mounted LEDs, any color can be mixed at any pixel location, Uni-Pixel claims.
The films, which are microfabricated on inexpensive roll-to-roll manufacturing lines, use MEMS-patterned structures to deflect light from guides to pixels with sub-10 micron micromirrors that are said to react 1,000-times faster than liquid crystals (TMOS displays update pixels in microseconds compared to milliseconds for LCDs).