Ortustech, a joint venture of Casio and Toppan Printing, showed off a 4.8" screen with a 1920 x 1080 pixel resolution! The display has a pixel density of 458 pixels per inch and offers a viewing angle of 160-degrees. It's unknown if the screen will ever enter mass production.
Orustech Japan has teamed with Casio and Toppan Printing to develop the world’s smallest 1080p display. It measures 4.8 inches diagonally and has a native resolution of 1920x1080 at an extremely high density of 458 pixels-per-inch (ppi). This is a much more densely packed display than the iPhone 4’s vaunted 3.5-inch Retina display, which has a 960x640 resolution at 326ppi.
In order to deliver a display of this level of resolution in such a small area, Orustech has developed a new display technology it refers to as Hyper Amorphous Silicon TFT, or HAST. It also has a wide viewing angle of 160-degrees and has support for 16 million colors.