Sharp have been rumoured to be building screens for Apple’s future iPad 3. The iPad 3 is expected to have a Retina-like display resolution. The current iPad has a resolution of 1024 x 768 that equates to 132 pixels per inch (ppi). This is similar to the iPhone 3GS which was the last pre-Retina iPhone. It was a 480 x 320 resolution at 163 ppi. The screen for the iPhone 4 and carried onto the latest iPhone 4S was doubled in both directions to 960-by-640-pixel resolution at 326 ppi.
There are sound compatibility issues with doubling the resolution in both directions since low resolution apps can easily be scaled to work on high resolution screens. It follows that the same approach would be taken when upgrading the iPad to a higher resolution in the future. An iPad 3 with a doubled resolution would be 2048 x 1536 with a 264 ppi assuming no change in the physical size of the screen.
This would give an iPad 3 some 3.1M pixels, compared with 0.6M pixels on an iPhone 4S. Coupled with the physical size, this number of pixels would require a second backlight for the iPad 3 and add to battery life – as would the pixel count. The news that Sharp may be providing an LCD screen based on IGZO (indium, gallium, zinc oxide) technology.
