Sales of 3-D TVs could increase fivefold this year, as more televisions come with the technology built in, and the range of available content steadily increases.

A report published this week by market research company In-Stat suggests that sales of 3-D TVs could increase by 500 percent in 2011. Last year, only 1 or 2 percent of the 210 million TVs sold worldwide were 3-D-capable.

“It’s not consumers demanding it,” says Michelle Abraham, author of the In-Stat report. “It’s manufacturers making it a [standard] feature of their larger screen sets.”

Paul Gagnon, director of North American TV research at DisplaySearch (a research company owned by the same parent company as In-Stat), says many consumers remain confused about 3-D TV technology. On Monday at the Society for Information Display’s Business Conference in Los Angeles, Gagnon said manufacturers also detracted from 3-D TV by introducing several other television technologies last year.

“In 2010, 3-D TV had to share the stage with LED backlights as well as with Internet-connected TVs,” said Gagnon. “You can’t focus on all messages all the time and expect consumers to understand them.”

To remain profitable, manufacturers are focused on adding premium features. Until about 2007, a major new technology was introduced about every two years. Now, says Gagnon, the cycle is as short as six months. “Especially in the U.S., we see shorter and shorter development cycles,” he said.

According to a survey conducted recently by Sony Entertainment, only 54 percent of people know that 3-D TVs can also show regular 2-D content. Most consumers also say that these sets are still too expensive (averaging around $1,600 compared to about $500 for a 2-D TV, although the price has come down significantly in the past year).

The availability of new content could help encourage adoption of the technology. Representatives from LG, Sony, and ESPN detailed plans to create more 3-D content at the display conference.

In February, ESPN began offering 3-D content 24 hours a day on its 3-D channel. Xfinity and DirecTV also launched 3-D channels this year. “Cable distribution is key,” says Bryan Burns, a vice president at ESPN. In 2010, there were only about 40 3-D Blu-ray movie titles available, according to DisplaySearch, and it will take time to build that up.

Burns says ESPN has learned many lessons in the year since it launched its 3-D channel. “We’re working hard on our production costs,” he says. At first, the network used two production teams to film 2-D and 3-D content, which doubled the production costs. Now they use what they call a “5-D” production system that more closely integrates the equipment and crew needed for filming both.

Several companies, including LG, also now offer 3-D TV sets that work with more comfortable, battery-free glasses. Unlike previous types of glasses, these also work when a user tilts his or her head.

“Auto-stereoscopic [glasses-free] 3-D won’t be here for a long time,” says Mike Abary, a senior VP at Sony.