Pixel Qi

2010 IEEE ACE award for "Emerging Technology with greatest  promise for financial success" winner: Pixel Qi, its dual mode screen provides both e-paper readability and full-color video.

Basically, Pixel Qi's screen is a transflective LCD, each pixel comprise both transmissive and reflective parts. It combines conventional TFT LCD and e-paper reflective display, so has both advantages:

• Power reduction
• Use anywhere - brilliant sunlight, offices, darkroom
• Readability: Reflective  mode for low power and e-reader applications
• High Color and speed for multi-media and PC type applications

Spec
Now, they support 10.1" display for DIY kit.

• Description           Parameter          
• Diagonal                   10.1"
• Resolution T             1024x600xRGB (transmissive)
• Resolution R             3072x600 (reflective)
• Brightness                165 nits typ (dark room)
• Brightness                 235 nits (room lighting)
• Brightness                 >1000 nits  (outside, sunlight)
• Color Saturation T      40% NTSC
• Reflectance               27% hemispheric
• BLU power                2W
• Panel Power              0.41W @30Hz
• Panel Power              0.54W @60Hz
• Interface                    LVDS
• Mechanical                235mm x 143mm x 5.2mm

Conventional transflective LCD

http://www.auo.com/auoDEV/technology.php?sec=transflective

(from: AUO website)

Traditional transflective use color filter to produce color for reflected ambient light, but light is lost in absorption after it passes through color filter twice. Furthermore, reflective parts would decrease the fill factor of pixel and the throughput of transmissive light from backlight.

Pixel Qi design

• For reflective light

Pixel Qi redesign every layer in the LCD - polarizers, retarders, filters, masks, electrodes, and liquid crystal. Most area of pixel is reversed for reflection. Because of no color filter, no light would loss but only back and white render.

Pixel

Polarizer and colorless retarder support the polarization and phase to reflected light from metal reflector, liquid crystal would modulate the retardance twice. This is how grayscale produced and make LCD look like as e-paper. Even in sunshine, reflective mode works pretty good.

• For transmissive light

Because of no color filter and most area reversed for reflective, Pixel Qi use RGB LED to make color , support efficiency light and low power consumption. In order to extract the light from backlight, Pixel Qi design recirculation for transmissive light to enhance illumination, by reflector and BEF.

But it still has disadvantage: Colorful

From the low color saturation on spec, this tell us the display can't compete conventional LCD in color saturation. Because its reflective part does not support color, even LED support pure color.

Market

Pixel Qi's display is a killer to e-paper. This display combine both advantage of LCD and e-paper. Reflective mode is good at supporting readability, low power consumption and bright ambient operation. Transmissive mode can display color and video, which beats e-paper most. In low power, it can support netbook another choice for display.

More
CEO Mary Lou Jepsen's blog
http://pixelqi.com/blog1/
Jepsen is famous for creating OLPC (One Laptop per Child) project.
http://en.wikipedia.org/wiki/Mary_Lou_Jepsen