LCOS

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LCOS - Liquid Crystal On Silicon

The LCOS technology is the newest one on the block. It uses the simplicity and cheapness of a standard LCD, and adds elements of the reflective technology perfected by D-ILA to produce an innovative solution.
          The 3-Chip version of the system beams pre-coloured red, green and blue light into three separate LCOS chips. The light is simply run through a polarizing filter and aimed at the chip. At the chip, the light pases through the LCD layer, reflects off the back surface and passes back through the LCD layer. The light then exits the chip and heads towards a second polarizing filter. The three separate coloured images are combined into one image using a prism, and then projected through stand lens optics onto a screen.

A single chip LCOS device uses a colour wheel (in the same way as the DLP single chip option) to create the full colour image.
          It is very likely that LCOS will quickly move to completely replace conventional LCD, largely because of the cost effectiveness of production and two major optical advantages. The first of the two optical advantages are that the pixel pitch (space between pixels) is at least as good as and possibly better than D-ILA. Secondly, the quality of blacks can be enhanced due to the fact the light has to pass through the LCD layer twice before leaving the projector.

Lcos's principle advantage over other current display technologies is the reduction of visible pixelation on the projected image. The gap between the pixels is so small that even when the image is projected to a 3m diagonal, it is still not possible to see the edges of the pixels

DLP                            LCOS