Re color. The LCoS-type micro devices themselves are just addressable light valves. They do not have intrinsic color capability (except for some diffraction-based devices which appear to be a little less efficient overall). For bigger screen projection, three chips can reflect red, green, and blue images respectively, the outputs of which are optically combined into full color images.
For smaller devices (like look-in handheld devices), there is another way of achieving color, if the LC devices can switch from one frame of information to another fast enough. If the devices can switch fast enough (e.g., 1/180 second per color) to show the red, green and blue frames in say 1/60 second total, then one can use red LEDs to light the display for 1/180 sec, green LEDs for 1/180 sec, and blue for 1/180 second. That way, a single chip can yield a color display. The trick is the fast-switching LCD. I think Kopin has a demo of something like that, and maybe so does Display Tech. I'm sure any of the suppliers of these devices (including TFS) want to cover the fast-switching device market as well. Most of the normal LCoS-type devices don't like to switch that fast. It depends mostly upon the LC material used. If TFS doesn't have that capability right now, it's likely just a matter of time IMHO. JimA |
