Micron Technology: FLCOS

FLCOS(Ferroelectric Liquid Crystal On Silicon), derivative of LCoS, is used in projector.

(LCos: http://en.wikipedia.org/wiki/Liquid_crystal_on_silicon)

In 2009, Micro Technology acquired Displaytech, a specialist company of liquid crystal and display technology. (But in the same year Micro sold its CMOS image sensor division : Aptina imaging.)At the same time pico projector is regarded as a promising product. 

Single chip display panel can miniature the projection system- less components:

• Chip--consists of FLC (Ferroelectric liquid light modulator) and controller
• LEDs

Ferroelectric Liquid Crystal
FLC is one type of liquid crystal but different in chemical material.
More faster than conventional LC, FLC can switch at speed of 1/10,000 second (typical rise/fall time: 35us).

Why need so fast modulation speed?

Sequential color
Projector switch frames so quickly that it could mix the red, green, and blue pixels over time, instead of space. Such quick sequence would fool human eye like moving images principles.
Not like spatial distribution at the same time, sequential RGB frames provide high color fidelity and high illumination (-> less power consumption). Because no resolution or light is wasted in sequential color.

Hexagonal Pixel Multiplication (HPX)
Hexagonal pixels is that each row is offset by a half pixel (much like a honeycomb). This arrangement doubles perceived horizontal resolution and smooths diagonal lines performance.

Each pixel has low power SRAM to store image data for incredible fast RGB frame switch.
Micron points out that each frame has 6 sequential color subfrmes with 256 possible exposure levels for every subframe pixel. So SVGA(800x600) display calculates 173 million individual exposures every second(6 x 60 fps x 800x 600 pixels)
Each pixel must be controlled precisely and incredibly quickly.

More
Have you ever wonder how each pixel control the gray-scale of each color?
If you notice the video of youtube, you can see Micro mark "exposure 256".
Does that mean each pixel switch 256 terms to adjust the gray-scale?

60fps x 3(RGB) x 255(8 bit level-256) /each second, this mean FLC must switch fast as 22us
But FLC rise/fall time 35us --> Impossible!!!!!!

This problem is solved by algorithm of video technique : digital gray scale - bit plane, developed for sequential display.