It was only a matter of time before smartphone screens increased in pixel count to match the 1080p Full HD diplays most people have in their living rooms, so LG’s announcement of a five-inch IPS LCD with 1080 lines of vertical resolution should really come as no surprise. On the other hand, Apple told us at the time of the iPhone 4′s Retina Display unveiling that its 326ppi pixel density (960 x 640 on a 3.5-inch screen) was already high enough to make individual pixels indistinguishable, so why do we need the 440ppi offered by this new LG panel?
Display technology over the course of smartphone history has been nothing short of amazing. One of the first handsets to gain a widespread following, the Handspring Treo 600, had just a 160 x 160 pixel screen measuring 2.5 inches along the diagonal, which equates to a density of around 91ppi. In less than a decade following that device’s release, we’ve seen resolutions increase to 320 x 320, 640 x 480, 960 x 540 and with last year’s launch of the Samsung Galaxy Nexus, 1280 x 720. Now it looks like we’ll have 1920 x 1080 devices (the same resolution as many 24-inch desktop monitors) before the end of the year — slightly larger “phablets,” if not traditional smartphones.
At some point are you packing too many pixels into a relatively tiny display, i.e. don’t you hit a certain pixel density after which improvements are only very marginal? Well, yes and no. It’s true that you probably won’t be able to see any pixels on the iPhone 4S’ relatively small screen, held just feet from your eyes, making higher pixel counts somewhat unnecessary in that respect. However, the video content that we’re feeding to our phones continues to outpace their resolutions, requiring the 1080p TV episode you recorded last night to get downscaled to 720p or less.
From this perspective, smartphone displays cannot just benefit from 1080p native video reproduction, but even higher resolutions as content trickles out for the quadHD sets that will soon make it to market. Higher-res displays also allow later-model phones to better display images captured with their high-megapixel-count sensors, with an 8MP photo clocking in at around 3264 x 2448 pixels.
So while in some ways it seems unnecessary to keep increasing smartphone display resolution, in another way it makes total sense: screens should optimally be the same resolution as the source footage being played back. And since there seems to be no limit to the pixel densities we can achieve with our regular, full-size capture and playback devices, there will always be an incentive for our pocketable displays to match computing and home theater standards as closely as possible.