Industry sources have told Taiwanese news outlet Digitimes that production of the upcoming iPhone 5S will be limited to 3-4 million units in Q3 2013 due to a shortage of the fingerprint scanners to be used in the phone. Specifically, the sources cite difficulties in interaction between the fingerprint scanners and Appleās upcoming iOS 7 mobile platform. Production of Apple's next iPhone, commonly referred to be the iPhone 5S and is scheduled to be unveiled on September 10, could reach only 3-4 million units in the third quarter of 2013 compared to 10 million units as originally planned due to a delay in production of fingerprint sensors needed for the iPhone 5S, according to industry sources.