The Nokia Lumia 920 PureMotion HD+ screen explained: is this the best phone for Snooki?
LG used it in the case of Optimus G to indicate in-cell touch panel. The new Lumia certainly belongs to the high-res RGB crowd, but what about PureMotion?Now we know HD stands for high-res screens with at least 1280x720 pixels, and the Plus usually indicates an RGB "stripe" matrix arrangement in the case of Samsung, while
Nokia outed the white paper of its new screen technology, where the "+"sign stands for the WXGA pixel count, while PureMotion apparently stands for an aggregate of technologies that address the weakest points of mobile capacitive displays that have been around since they became mainstream with the iPhone introduction in 2007. Now, five year later, Nokia is trying to resolve all those issues in one fell swoop, and called it the PureMotion HD+ display. The "Pure" part winks at the PureView marketing term, of course, which has already been proven to work in enthusiast mobile devices like the 808 PureView.
With the Lumia 920's large 4.5" high-res screen, Nokia tried to address at once several issues that plague smartphone displays - poor sunlight visibility, motion blur, and the inability to operate them with anything but bare skin. Let's not forget also that at 332ppi, only a 4.3-incher like the Xperia S (342ppi) beats its pixel density, yet Nokia went much further with the 15:9 display than simply being satisfied with that, adding a number of important innovations to it. Let's delve into how the Finns did it.
The most pressing issue with smartphone displays, once they hit the HD resolution mark, we'd peg to be their outside visibility, especially under direct sunlight. To make a screen visible outside, you need great performance in one of two components - brightness or light reflection ratio. The iPhone 4S screen is brighter than the Super AMOLEDs in the Galaxy S II/III, but Samsung uses a layer with very low light reflectance, which improves its outside visibility.
The Nokia Lumia 900, on the other hand, has an even lower reflection ratio of its OLED screen, thanks to the ClearBlack polarization filter of Nokia, making it the best display for outside usage in independent comparisons. This comes to show that a combinatioin of both high brightness and low reflectance ratio will yield the best results, and that's exactly what Nokia did with the PureMion HD+ display of the Lumia 920.
The brightness is listed as 600 nits, which is 20-30% more than your average mobile display, but Nokia says the display automatically goes into peak brightness mode under direct sunlight, which it says is the highest brightness of all WXGA mobile screens. Now we don't know if peak brightness means something more than 600 nits, like on the Xperia P, which shoots up to 935 nits, but even if the peak luminance is 600 nits, Nokia adds a new version of ClearBlack on top for helping things out further.
Not that we've noticed much, if any, motion blur on our handsets while scrolling or watching movies, but Nokia claims your average mobile display pixel response rate is 23ms, while a rendered frame lasts 16.7ms, i.e. the pixels don't have time to go with the flow, resulting in blur and artifacts with fast moving objects on the screen, for example.
The way Nokia is overcoming this is applying temporary high voltage to speed up the individual pixels, essentially putting the whole panel in overdrive mode. Lab results show pixel transition taking sub-9ms this way, i.e. plenty of time to do one frame and get ready for another without any lag and blur. This way smooth 60fps rendering is achieved, Nokia says, regardless of how speedy the action is on the Lumia 920 display. Good stuff, but we have to again check with a final unit how much of a difference this makes in reality.
The Nokia Lumia 920 touchscreen is so sensitive, that once you hit that unlock button, you can demonstrably operate it not solely with the tip of your bare fingers, but also with nails, gloves, mittens, and even certain pens, no need for a special stylus. This finally combines the best of both resistive and capacitive touchscreens in theory, so you no longer have to use your nose on the ski lift when you get a call. The technology is developed by Synaptics, which you know from your laptop's touchpad, and called ClearPad 3250:
Nicole "Snooki" Polizzi will be glad the Lumia 920 exists too, as the classy way she pimps her eagle nails must not bode well for comfortable touchscreen operation. We kid, but Nokia indeed says nails are now possible, as well as some pens, but whether this hyper sensitive touch layer can lead to "butt dialing" in certain scenarios remains to be seen after we spend more time with the handset.
In the end we have to conclude that Nokia apparently threw a lot of the research that is going on in its labs into the Lumia 920, and we are glad the PureMotion HD+ screen was one of the recipients, since sunlight visibility and usability of capacitive touchscreens with something else than bare finger tips were areas that could definitely see improvement.