Sony has unveiled two rival products to Apple's iPad in a late bid to challenge in the tablet computer market.

The S1 device is similar to Apple's market-leading tablet but the S2 is a radical two-screen computer that can be folded up when not in use.

Sony said the S2 would combine Google's Android operating system with dual 5.5-inch screens when it goes on sale in the autumn.

It can also be used as a TV remote control and access Sony's film and TV download service.

"The 'Sony Tablet' delivers an entertainment experience where users can enjoy cloud-based services on-the-go at any time.

"We’re aiming to create a new lifestyle by integrating consumer hardware, including ‘Sony Tablet’ with content and network,” said Kunimasa Suzuki, a corporate executive at Sony.

Apple, Motorola and BlackBerry already have rival products in the tablet market.

Sony did not say how much its new products would cost.

Details

S1 has a 9.4-inch display for enjoying the web and rich content on a large screen. "Its off-center of gravity design realizes stability and ease of grip as well as a sense of stability and lightness, offering comfortable use for hours," Sony said in a statement.

S2 has two 5.5-inch displays that can be folded for easy portability. In contrast to existing tablets, its unprecedented dual screen presentation allows its displays to be combined and used as a large screen or for different functions such as playing video on one screen while showing control buttons on the other.