The Invisible Television.

A new prototype from Panasonic has been shown off at the CEATEC electronics expo in Japan this week.

When switched on, it's just like a normal TV. When switched off, it's as transparent as glass, meaning you can see the wall or shelving behind.

Panasonic describes it as the "future of display screens" - although as you might expect, the company's staying tight-lipped about the technology behind its transparent TV, just in case its competitors have something similar in mind.

The screen is made from a fine mesh embedded in a glass panel.

Importantly, the screen uses the latest OLED (organic light-emitting diode) technology, where each pixel lights itself (rather than being lit from behind).

Traditionally, OLED panels put a thin layer of plastic between two electrodes on top of a glass slab. Because of this, when the electric signal disappears, the slab can look virtually transparent.

OLED technology requires very little power too, which is why panels like this can be so thin. Eventually, tech firms are hoping to develop flexible OLED screens that you can bend or even roll away.

Panasonic originally showed off the technology at CES in Las Vegas earlier in the year, but the company's engineers say the latest version of their invisible television looks even more transparent when switched off, and brighter when switched on.