Apple is rumored to be testing a new screen technology for the next iPhone, manufactured by Innolux, called “Touch on Display”. It's said to be both thin a durable, and could potentially fix problems that have been associated with the current in-cell technology, namely buggy touch responsiveness when swiping at extreme angles. This according to The China Times.
The current in-cell displays are manufactured by a number of companies, including Japan Display and Sharp Display. In-cell display was one of the new features of the iPhone 5, and made it possible for Apple to decrease the thickness of the device.
If Apple is looking to replace it, they’ll want to find a panel that allows them to keep the iPhone as thin as it is now. Not much is known about the next iPhone, which Apple is currently testing, but more information is sure to crop up before it launches sometime this year.