The news of a hacked system forced Sony to shut down its PlayStation Network last week, overshadowing the unveiling of two prototype tablets in Tokyo.

While its competitors have recently revealed new tablets, including RIM's Playbook and Motorola's Xoom, Sony is still trying to grab market share from the undisputed leader: the Apple's iPad.

The first prototype tablet is code-named S1 and features a 9.4-inch screen. The tablet has a wedge shape which the company says makes it easier for users to hold. The shape was inspired by the feel of a magazine in a reader's hands.

The second tablet is code-named S2 and has a clamshell design with twin 5.5 inch screens. It can be folded so it fits in a bag or jacket pocket. Sony is hoping the unique design inspires developers to create innovative applications that make use of the two screens.

Both tablets are PlayStation-certified and will run an upcoming series of Android games from Sony and other game studios. The familiar PlayStation control buttons appear on screen.

Sony hopes the two tablets will earn a spot in the crowded tablet market around the world later this year.