Anticipated shortages of the Retina iPad Mini are linked to burn-in problems Sharp is having with its IGZO LCD panels, an industry source claims. The burn-in is thought to be caused by malfunctions in thin-film transistors. The source notes that while the burn-in is invisible to the eye, it still doesn't meet Apple's quality standards.
The resulting low yield rates have slowed down
overall Mini production, prompting Apple to turn to Samsung. At the moment, LG Display is thought to be handling 60 percent of Mini display production, using amorphous silicon (a-Si) for its TFTs, which doesn't have the burn-in problem. Sharp is responsible for the remaining 40 percent of screens, but could lose at least some orders to Samsung starting in 2014. The latter uses another technology without burn-in issues, low temperature polycrystalline silicon, or LTPS.
The account is consistent with other recent rumors
pointing to Sharp as the weak link. LG has also been rumored as having trouble though, which may mean that the Mini's display is simply difficult to manufacture under any circumstance. The screen uses the same resolution as the 9.7-inch iPad Air, but compressed down to 7.9 inches. That gives it an incredibly sharp pixel density, which may be easy to botch.