Apple is reportedly in the process of testing larger iPhone and iPad screens with a number of Asian suppliers. In recent months, Cupertino has asked for prototype iPhone screens larger than 4 inches and displays to use with the iPad that are just under 13 inches according to sources as reported by the Wall Street Journal.

At present, the iPhone 5 ships with a 4-inch screen while the full-sized iPad carries a 9.7-inch display. The smaller iPad mini utilizes a screen size of just 7.9 inches. Whether or not larger screens will ultimately make it into future products is unknown although the Journal points out that Apple routinely tests multiple concepts before a final design is selected.

During an earnings call a few months ago, Apple chief Tim Cook acknowledged that some are interested in a device with a larger screen. He pointed out, however, that existing "phablets" sacrifice color quality, resolution, white balance, brightness, reflectivity, screen longevity and other features - tradeoffs Apple will not make just to ship a larger display iPhone.

Apple's next iteration of the iPhone, widely referred to as the iPhone 5S, is expected to ship as early as next month. Most believe the handset will retain the same outward appearance as the current generation iPhone but with faster hardware inside.

On the opposite end of the spectrum, Apple is said to be preparing to ramp up production of a new iPad within the next few weeks. Sources say the tablet will retain the same 9.7-inch display but will be lighter and thinner than the current generation slate.