For pixel density, the Apple iPhone's Retina display has been the top dog of the smartphone display tech world for some time. That has now changed. LG just unveiled their newest truly HD smartphone display. It's a bit on the extra-large size, but it definitely packs a gorgeous punch. Their new AH-IPS (Advanced High Performance In-Plane Switching) LCD screen is 5 inches, and has a true HD 1920x1080 (1080p). Furthermore, this new screen tech packs in a whopping 440 pixels per inch pixel (ppi) density, compared to the iPhone's 330ppi display. LG shared a statement along with the announcement of the new screen, "The naked eye is unable to distinguish between individual pixels."

Additionally, their new AH-IPS technology, provides wider viewing angles, an improved color palette and faster touch-response times. Here's a quote with some final details,

The new LG screen, which will be released in the second half of 2012, will be on display in June at the SID 2012 Display Week trade show in Boston.
Source: CNET