Pabloandres,
All but the most expensive DLP projectors use only one DLP chip, whereas LCD and D-ILA projectors use
3 chips - one for each of the primary colors of light - red, green, and blue.
The DLP makes one chip do triple duty by putting a "color wheel" with red, green, and blue sectors on
it in front of the DLP chip.
So whereas the LCD and D-ILAs project all three colors simultaneously, single chip DLP projectors
flash the red, green, and blue images sequentially on the screen. They rely on the "persistence of
vision" effect of your eye to blend the images together. For example, if you move your head or
eyes quickly, and hence change where the image falls on your retinas - the 3 images won't blend
properly - and you get rainbows.
Greg