We’ve seen televisions and PC monitors with 4K resolutions. Now, a compact mobile display has joined the club. Japan Display has developed a 12.1" panel with a 3840×2160 resolution. The resulting pixel density works out to 365 PPI—the highest we’ve seen from a display suitable for notebooks and tablets.

The press release doesn’t describe the underlying display technology. However, the screen covers only 70% of the NTSC color gamut. The 160° viewing angles are a little narrow, too. I wouldn’t be surprised if there were TN panel tech under the hood. Other specifications include a 1000:1 contrast ratio and a 500 cd/m² brightness rating.

The display is surrounded by a thin 2-mm frame that should allow for narrow bezels. It looks like the whole contraption is 6.8 mm thick, though. We probably won’t see this puppy slipping into the iPad Air anytime soon. Japan Display says the 4K screen is suitable for high-end notebooks and high-performance tablets. Translation: it ain’t cheap.

Although the prospect of ultraportable notebooks and tablets with 4K displays is tantalizing, I’d rather not sacrifice color reproduction for a higher pixel density. It’s probably only a matter of time before similar displays are available with wider color gamuts and viewing angles. Thanks to Engadget for the tip.

Update: Turns out the NTSC color gamut is much wider than the sRGB gamut commonly used in the PC world. sRGB has only about 70% of the colors in NTSC, so this 4K display could offer close to full coverage of the sRGB gamut, matching IPS screens like the iPad’s Retina panel. Thanks to TR reader Joel for the clarification.