Originally Posted by irkuck
There is still life in OLED: New Samsung Galaxy IV has full HD 5" OLED display (pentile though). Since this mobile is expected to sell in many tens of millions there is enough volume to make the display production economical. However first reports indicate the display is bright and saturated, it has a blue tint, so not a big revelation comparing to LCD.
I don't know what sub pixel structure Samsung is using in the S4 but DisplaySearch reports
We believe that Samsung has revamped its sub-pixel layout to achieve FHD resolution using its existing FMM (Fine Metal Mask) evaporation process. Samsung might be using the advanced s-stripe with hexagonal and diamond-shaped pixels to achieve the higher ppi.
The s-stripe arrangement has several advantages. First, the display readability is significantly improved compared to traditional Pentile, which has two sub-pixels per pixel. S-stripe has three sub-pixels per pixel, and an advanced design may have five. The second advantage is that s-stripe may enable longer lifetimes for the display. Normally, the blue organic material has the shortest lifetime; in s-stripe, the blue sub-pixel domain is larger than that of the other colors. This means that the luminance per area can be less for blue, which is less stressful. In this way, the entire OLED display’s lifetime can be extended.
If an s-stripe or advanced version sub-pixel layout is the ultimate solution for AMOLED to achieve 400 ppi+ resolution, then it could be a competitive advantage for Samsung.
The S4 will also have an Adapt Display
feature according to Raymond Soneira, Displaymate's display guru who has previously criticized Samsung for the lack of calibration on their AMOLED displays - the colors are too saturated, the whites are too blue, and the intensity scales are too steep.
As Raymond points out, Samsung's own S4 site shows a CIE chromaticity diagram and a gray scale level picker (see screenshot above). This leads Raymond to believe that the S4 will have extensive color, white-point, and display calibration adjustments. This could be a "major display advancement and a win for Samsung and AMOLED displays" - according to Raymond.
Raymond adds that this multi-parameter interactive display calibration software will make it possible for such an OLED to accurately provide any desired color gamut, white point color temperature, and intensity scale. This is actually much harder for LCDs to implement because they are internally a non-linear analog display technology at the panel level, whereas OLEDs are digitally driven via Pulse Width Modulation (PWM).
LCDs have a non-linear and irregular S Shaped Transfer Characteristic (light output versus drive signal) that makes it harder to accurately implement the various calibration variables. On the other hand, OLEDs driven with PWM respond in a straight-forward linear fashion that makes it easy to accurately calculate and precisely adjust the various parameters.