Here's something to think about for anyone who shelled out money for a new HD TV recently: TV makers are trying to get you to cough up more money — and sooner. The newest technology is called Ultra HD — and it's among the products being shown off at the International CES in Las Vegas this week. TV manufacturers are trying to get people to upgrade their TV sets a little faster than they are used to. These days, most Americans buy new TVs once every seven years. But companies making the Ultra HD sets are hoping that if you see the picture quality, you'll be quicker to upgrade up for a new set. Already, major players in the streaming category like Netflix and Amazon say they are offering movies in the new format.