The tech blogosphere has been rife with rumors that LG Electronics plans to unveil a portable 3D television at the Consumer Electronics Show in Las Vegas.

LG has already announced several home entertainment devices geared to 3D televisions, all of which will be shown at the CES, which starts Jan. 6. Most of the devices so far are designed to make 3D televisions a better home theater experience, such as sound systems and blu-ray disc players. The company also announced Monday that it planned to roll out what it claims is the largest 3D-capable LED television - 72 inches.

The new device has shown up on several technology blogs and looks like a portable over the air television, if smaller. It will supposedly be glasses-free. Beyond that, it isn't clear what its range of features is.

LG did not return calls for comment.

3D televisions have been a major theme for many home electronics makers, including such giants as Panasonic, Sharp, Sony and Samsung. But they have not sold as well as many industry players hoped they would.

One problem is content: there isn't much out there and the biggest 3D film yet, Avatar, is only available on one brand of television - Panasonic. British Sky Broadcasting and DirecTV both have a 3D channel, as does ESPN. The Discovery Channel also launched a 3D offering.  But there are still relatively few options for owners of 3D televisions, which can retail for $1,000. And the need for special glasses on many models could prove an obstacle for some buyers.