The iPad 3 will likely use a new dual-LED backlight design for its high-resolution Retina display, reports DigiTimes, as the single LED light bar used in the iPad 2 is not bright enough for the new panels.
Citing sources from within Apple’s vendors, the report claims that Apple has been offered two possible options to replace the current backlighting: a brighter single-bar LED with dial LED chips or a system including two LED light bars.
Apple is believed to be adopting the dual light bar system due to its superior performance, and also due to there being no present issues with cooling and battery usage in the iPad 2.
The Retina panels believed to be included in the upcoming tablet are expected to have a pixel density of 264 pixels per inch (PPI) or higher, which is at least twice the 132 PPI on the iPad 2. By comparison, the iPhone 4 has a pixel density of 326 PPI.