Vendors have been plugging the green credentials at the IFA consumer electronics show in Berlin, through whether from fear of destroying the planet or under pressure from governments or the market is far from clear. Sharp, Panasonic ad Sony all declared that their latest screens draw less power than previous models.

Sony and Panasonic screens sensing ambient light and adjust the brightness accordingly, saving sometimes 50 percent of the power drain. But as we report today, screens are also getting bigger - the one picture above is 150in.

Also noticeable is that they are using WirelessHD instead of Ultrawideband (UWB) for short-range wireless transfer of high-definition content. Current data rates go up to 4Gbits/sec but the theoretical limit is 25Gbits/sec. Multiple aerials get round the need for lightof-sight opration because the signals bounce of the walls. And of course the 60GHz band is way above the frequencies used for other data links linke Wifi.

Where this leaves UWB is anybody's guess.

Sony's XEL-1 TV (above right and left) looks great though it is very small - about the size of a portable DVD player. No prices are available yet but I guess it will be a long time before we see these screens in notebooks. An advantage of the fact that the Oled pixels generate their own light is that you should be able to switch them off. That means if you are doing something that only uses half the sreen, you don't waste power on the other half.