Apple is still singing the praises of their "Retina Display" even though other companies, like Samsung, LG, and HTC have long since passed Apple's 326 pixels per inch (ppi), but that "Retina Display" is all their customers hear, not the ppi. Samsung's Galaxy S4 has 440ppi, the LG G2 has 424ppi, and the HTC One has 469ppi that simply stomp the iPhone 5s' still meager 326ppi - and why should they up the ante when the iPhone continues to sell at 326ppi.
Well there is a new kid on the block that is kicking everybody's respective ppi - President of Japan Displays, Shuichi Otsuka, says Japan Displays is pumping out a new 5.4-inch display, with a resolution of 2580 x 1440 pixels, which translates into a whopping 543ppi! A Chinese manufacturer, Vivo is already working a smartphone, the Vivo Xplay3S, with their own version of the 2560 x 1440 display, but theirs is a 6-inch display, so the ppi is slightly less than Japan Display's 5.4-inch, since the pixels are packed tighter on the smaller screen. Japan Displays is also working on a 6.2-inch version of the screen, but it "only" manages 473ppi due to its larger size.
One might ask themselves if this screen technology is a little overkill because our eyes will never be able to appreciate it, since the unaided human eye cannot really distinguish differences beyond 300ppi. I guess many people said that when the last big jump was from 720p to 1080p, so will it really hurt anything to go higher in display density, as long as it does not affect our battery life? Japan Displays claim their new 5.4-inch display is only 1.12mm thick and offers 160-degree viewing angles with a low power consumption. If these claims hold up, it may be that the US will see these screens in 2014 or 2015.
With Samsung and LG working on flexible displays and batteries, it may be that 1080p is all we will see here in the foreseeable future, but that is alright by me - my Galaxy Note 3's display with 386ppi just suits me fine. Let us know in the comments or on Google+ how you feel about display pixels and the newest 1080p screens on the market...are you happy, or do you want more.