Apple is expected to unveil its rumored 7-inch tablet next month. However, Amazon may ruin Apple's plans with the introduction of low-priced tablets and e-readers.

Yesterday, Amazon revealed its slate of tablet computers, including an updated version of Kindle Fire. It seems that Amazon is trying to draw more consumers in its expanding portfolio of streaming video content and e-readers.

In a media event in Santa Monica, Calif., the online retail giant introduced a new Kindle Fire with a high-definition screen and dual antennas, as well as a self-lighting Kindle e-reader device.

"Last year, there were more than two dozen Android tablets launched and nobody bought them," said Amazon Chief Executive Jeff Bezos at the event, referring to Google's mobile-device operating software.

The new Kindle Fire HD device will come in two screen sizes and features a front facing camera, for $199 to $299, said Mr. Bezos. Moreover, an updated version of Amazon's original Kindle Fire tablet will ship on September 14 for $159, he said.

In an even more direct challenge to the iPad, a 4G version of the larger Kindle Fire HD will sell at $US499 -- the same price as a basic iPad.

There were rumors that Amazon is also developing its own smartphone to take on Apple's latest iPhone that is supposed to be released by year-end or early next year, officials at Amazon's parts providers who declined to be named said in July.

The new range of devices is expected to pose a threat to other 7-inch tablets like Google Nexus 7, Samsung Galaxy Tab 7.7 and upcoming iPad Mini. Because of the gadgets' affordable prices, there is a great possibility that it will attract a lot of consumers.

Amazon grew as the world's largest online retailer by selling different goods. Now, it is developing affordable hardware devices. The tablets are one of the devices that are expected to hit the market during the holiday season.