The red and blue sub-pixels in the PenTile Matrix structure. The blue is big because efficiencies are generally lower for blue. But why is the red so big? So I asked Joel Pollack, President of Nouvoyance. He replied. And here it is in full:
Let me try to answer your question. The goal is to achieve the same amount of aperture for red, green and blue to balance the chrominance, but we double the number of green subpixels to maintain the full resolution of green. The resolution of red and blue is half that of green. Nobody can really see the degradation of blue resolution due to the physiology of the human vision system. While red resolution is easier to perceive than blue it is not quite as important as green, so we have chosen to take some hit in red resolution than can be noticed in the unusual circumstance of saturated red on a black background. It is far more likely to experience a fully saturated green on a black background.
So there you have it. Got questions? Let me know.