For full disclosure, I am part of the team that has developed PenTile technology. I wanted to jump in here and set the record straight regarding polarization and PenTile. All modern LCD screens use the twisted nematic (TN) effect. LCD functionality is entirely dependent upon the use of polarizers as the LCD effect works using polarized light. One polarizer is needed on the input side of the TN layer to polarize the light and a 2nd polarizer is needed on the output side to “analyze” the light. Typically the axis of polarization of sunglasses is along the vertical for the purpose of blocking the glare of light reflecting off of water or from your car’s hood. Light reflected from horizontal surfaces becomes horizontally polarized so a vertically oriented polarizer acts to block that light.
LCDs typically have linear polarizers, just like your sunglasses, but the axis of polarization is generally set at 45 degrees to vertical so that in either portrait or landscape view polaroid sunglasses do not block the light. Some special applications use what are called circular polarizers to that there is no angle that a linear polarizer can be oriented to block light.
Now for the key point— PenTile technology has nothing to do with polarization or the choice of polarization. Display technology can use whatever effect is used to gate the light and it still acts with PenTile technology in the same way. It also has no effect on viewing angle, but is entirely dependent upon whatever wide viewing angle (WVA)technology is chosen for use in a given display.
The RGBG layout, referenced by 640k, is only used in PenTile OLED displays. OLEDs do not intrinsically require polarizers, but today’s OLEDs, like the one used in a Nexus One, also uses a polarizer to cut glare for enhanced viewing performance outdoors. This too is oriented at 45 degrees to the vertical and horizontal. Again, PenTile has no impact on this characteristic. For further info on PenTile please visit
PenTileBlog.com.