Next-generation TMOS displays closer to mass production
October 21, 2009
Uni-Pixel, a company based in Woodlands, Texas, has announced it is about to start mass production of a thin-film to be used in time-multiplexed optical shutter (TMOS) displays, a next-generation display technology that exploits retinal persistence in the human eye and promises significantly better performance than CRT, LCD and OLED displays with, among other things, great durability and dramatically improved energy efficiency.
The vast majority of displays available today use spatial superimposition of a synchronized red, green and blue light, each shining with a specific intensity, to create millions of color combinations. For instance, in LCD displays each pixel is made up of three RGB-colored dots that can take up discrete values over a 6- or 8-bit range: when watching the pixels from a distance, the human eye blends these three components together and perceives a single color over a total 18- or 24-bit range respectively.
TMOS displays harness a different principle in human vision: rather than superimposing the three components spatially, they do it temporally, exploiting the retinal persistence by intermittently sending just one of the three components at a time at very short intervals, and letting our brains "do the math" by adding the colors.
This approach greatly simplifies the manufacturing process, basically subtracting components from existing LCD lines and reducing others — such as the thin-film transistors for the RGB dots — by a factor of three, resulting in monitors that are 60 percent cheaper to manufacture than LCDs.
Because each layer placed between the top and the bottom glass sheet reduces the monitor's overall light output (each layer acts as a filter), removing components and simplifying the rest makes TMOS displays highly energy-efficient, letting through more than ten times as much light as a conventional LCD screen. Intuitively, this means one could obtain the same picture brightness using less than one-tenth of the power.
The intermittent red, green and blue light come from side-mounted LEDs that illuminate the bottom glass layer. Applying a voltage to the specially-developed film causes it to deform downward and touch the bottom glass, routing light from LEDs up to a particular pixel. The routing is done with the help of tiny mirrors, each less than 10 microns in size, that can manipulate the signals very quickly and achieve refresh rates 1,000 times higher than in LCD displays.
This simple but seemingly very powerful architecture also has other advantages: for instance, because of its small pixel size, it will be possible to reach densities as high as 300dpi. But the figure that might well be the most impressive is the projected display's life. The first component expected to fail in a TMOS display is one of the three LEDs, each of which have a life of 100,000 hours under continuous operation. However, TMOS displays use the three LEDs intermittently, which puts display life to approximately 300,000 hours, much more than LCDs or OLEDs.
"It is our plan to have film production begin in low volume this coming quarter for these initial customer orders and then ramp to high volumes for additional opportunities in the beginning of 2010," UniPixel's president and CEO Reed Killion explained.