Researchers from AU Optronics developed an AMOLED display that uses four primary colors (Red, Green, Blue and Yellow). They say that this design is more efficient than an RGB panel by 16%. The AMOLED panel is 4.65" 720p (317 PPI).
RGBY has been used by Sharp for their Quattron LCD displays (Aquos TVs) for a long time. Sharp says that adding another color increases the range of displayable colors (although the content itself does not provide the yellow color information, which means the TVs need to use software processes which results in less accurate colors).
Comments
I think it's more like the opposite of PenTile. In Pentile, you use 2 subpixels per pixel. Here the display has 4 subpixels per pixel. For the same display size and resolution, it will have twice the subpixels compared to a pentile display.
Instead of RG BG, they do RG BY ? Is it the trick they are actually doing?
BG RG BY RG