Apple's Retina display may have some fierce competition from Japan. 

Japan Display Inc., a joint venture bringing together some of Japan's biggest, recently demoed a 12.1-inch tablet screen that offers 3,840x 2,160 or 4k resolution at the FPD International 2013 exhibition this week.

The screen even remains less than a tenth of an inch thick despite the high-resolution while being 365ppi, compared to the new iPad Air's 264ppi, and uses a low temperature poly silicon technology (LTPS), allowing it to consume a mere 3.6W at 500cd/m2.

With a significant amount of money from the Innovation Network Corporation of Japan, JDI was established in April 2012 and regrouped the LCD operations of Hitachi, Sony and Toshiba. JDI demoed a 5-inch full-HD panel, which was the panel that made its way in the Sony Xperia Z and Xperia Z1 in November last year. 

JDI is one of the screen suppliers for Apple and has close ties with the iPhone maker. Earlier this year, Panasonic introduced a 20-inch Windows tablet sporting a 4K display at International CES 2013.

It's worth noting that the human eye really wouldn't be able to tell the difference between ultra-HD display and standard HD. Once someone gets used to 720p, there's no difference to the human eye up through 1080p, according to reports. That gives rise to the question of the ultra-HD's usefulness.

One company who could benefit from the high resolution displays is Microsoft and its new Modern style apps. Along with looking good on 720p, 1080p or 4K, it's easier to use on touchscreens.

There isn't any specific information on when the market might see the 12.1-inch 4K displays, so don't expect anything before the end of 2014. Until then, the collaborative has revealed a photo of what the display looks like. How that represents a visual representation of the real thing is yet to be seen.