Japanese electronics giant Sharp unveiled a line of 3D televisions Monday, joining rivals Samsung Electronics and Sony Corp. in an increasingly competitive sector the industry hopes will drive profits.

Sharp's first line of three dimensional liquid crystal display TVs will start selling in late July in Japan before roll outs in the United States, Europe and China by the end of the year, executive vice president Masafumi Matsumoto said.

The four 3D Aquos "Quattron" models incorporate what Sharp has called the world's first four primary-colour 3D displays, adding yellow to the traditional red, green and blue for more brightly defined images.

As with existing 3D TVs, the Sharp sets will require the viewer to wear special glasses, the company said. The sets will enable images created in 2D format to be viewed as 3D.

Sharp also announced it would launch in July two new Aquos Blu-ray recorders that support playback of high definition 3D disks.

In April Sharp unveiled an LCD touchscreen that shows 3D images without requiring special glasses, for potential use in mobile phones, digital cameras, digital photo frames and games consoles.

The entertainment and technology industries are gearing up to take advantage of the 3D bandwagon as the technology becomes increasingly mainstream and its popularity rises in the wake of Hollywood blockbusters such as "Avatar".