Sharp Corporation has developed what they are claiming as the world’s first four-primary-color 3D LCD TV. Obviously requiring you to wear special 3D glasses, the 3D LCDs use a system based on time-sequential display technology with special active LC (liquid crystal) shutters in the glasses. In this system, images intended for the left and right eye are displayed on the LCD screen sequentially, alternating between the two perspectives. The LC shutters in the special 3D glasses are synchronized with this display, “opening” (becoming transparent) and “closing” (becoming opaque) in such a way that the left and right eye see separate images. The human brain combines these two slightly different images to create the perception of depth in a three-dimensional image. Sharp claims that displaying 3D images on a conventional display using this system resulted in low brightness and crosstalk.
Sharp’s four-primary-color technology utilizes four primary colors, adding Y (yellow) to the three conventional primary colors of R (red), G (green), and B (blue). According to Sharp (and most people at CEDIA 2009, too), this technology contributes to brighter, more vivid colors thanks to higher light transmission efficiency through the panel and a wider color gamut (range of colors that can be reproduced), which had been difficult to attain on conventional three primary color displays.

Sharp’s actually set up an educational site on their 3D LCD technology at (but it’s all in Japanese?!?): http://www.sharp.co.jp/3d-tech/