Apple is testing up to five different screen types for its rumoured iPad Pro – including an Ultra HD version – according to Chinese website PadNews.
The company is said to be testing 2K and 4K screen technology, for use with the new iPad. The recently released iPad Air, which features Apple's Retina display, already has a screen resolution of 2048 x 1536 pixels. This to many could already be classed as '2K'.
However it is rumoured Apple are also looking into screen resolutions of at least 3840 x 2160, placing it firmly in the '4K Ultra HD' category.
It is also rumoured that Apple could release two tablets in 2014, both featuring a 12.9in display. A 2K display could be unveiled in the early part of the year, with the 4K variant emerging in October.
Apple hasn't confirmed these rumours to be true just yet – so as ever, they are to taken with a pinch of salt.
The idea of a 4K tablet isn't entirely absurd. Panasonic has already produced such a device, unveiling it at CES 2013. It is expected to bring it to CES 2014 as well, with other manufacturers possibly following suit.
Ultra high-definition 4K screen technology is the current trend among TV manufacturers, with many already producing sets that boast incredible detail next to conventional HD displays.
Apple itself has been subject to rumours surrounding a possible Apple 4K TV set for 2014. But this still very much in the rumour stage at the moment.
Whatever technology Apple may have up its sleeve, we'll report any new information as and when we hear it (so long as it seems reliable...).