Amazon has unveiled four new Kindle Fire models, including ones with larger screens, as the online retailer steps up competition with Apple ahead of the holiday shopping season.
Amazon unveiled the larger Kindle Fire amid expectations of a smaller iPad from Apple.
The larger Fires will have screens that measure 21.8cm diagonally, compared with 24.6 cm for the iPad. The original Fire had 17.8cm screens. The speculation on the mini iPad is that it'll have a 19.9cm screen.
Apple isn't commenting, but it has an event scheduled next week during which it is expected to at least announce a new iPhone.
The Kindle Fire is an effort to take a larger share of a tablet computer market dominated by Apple's iPad. Amazon has been selling lower-priced tablets at thin, if any, profit margins to boost sales of digital items from its online store.
Amazon is coming out with a high-end version called Kindle Fire HD. It will have two Wi-Fi channels for faster transfers. That will be crucial for high-definition movies and other large files, CEO Jeff Bezos said.
The HD model will also have more storage, starting at 16 gigabytes, compared with 6GB for the old Fire. It wasn't immediately clear what the updated basic model will come with. The iPad also starts at 16GB.
Bezos noted that the operating system takes up about 2GB, leaving an 8GB model with just 6GB.
"For a high-def device, 8GB is dead on arrival," Mr Bezos said.
Amazon also unveiled a premium Kindle Fire model, one with the ability to connect to the 4G mobile networks that phone companies are building. It will come with 32GB of memory and a 22.6cm screen.
Amazon also refreshed its line of stand-alone e-readers. Called Paperwhite, the new e-reader model has a black-and-white screen. It promises 25 per cent more contrast. Bezos said "the whites are whiter, and the blacks are blacker".
The Paperwhite has a light source. Mr Bezos says the device is "perfect in direct sunlight". Tablets such as the iPad and the Fire don't work as well in bright light because they are lit from the back.
Mr Bezos says the light on the Paperwhite is directed down at the display. The device promises eight weeks of battery life, even with the light on.
There's also a model with 3G mobile connections.