Apple is preparing to launch 32-inch and 37-inch television sets in the US next year, backed up by a rich library of on-demand content, it has been reported.

Digitimes quoted "industry sources" as saying that suppliers expect Apple to enter the flat panel television market in the second or third quarter of 2012.

The technology blog said that Samsung has already begun producing chips for the so-called "iTV" connected sets, while Sharp will make the displays.

Previous reports have claimed that Apple will incorporate the Siri voice control assistant from the iPhone 4S into its iTV sets, enabling users to change channels and access content with their voice.

However, it has also been suggested that Apple will not release standalone TV sets, but instead bring Apple TV functionality to its new range of iMac computers.

Speculation that Apple intends to make firm strides into the TV market reached new heights after Steve Jobs's official biography revealed that the Apple co-founder said before his death on October 5 that he had "finally cracked" how to build an integrated TV device.

Jobs told his biographer Walter Isaacson: "I'd like to create an integrated television set that is completely easy to use. It would be seamlessly synced with all of your devices and with iCloud. It will have the simplest user interface you could imagine. I finally cracked it."

There is other evidence to suggest that Apple is working on a TV project, including a filing at the US patent office in October for a "real time video process control using gestures".

This application included using infrared, motion and other sensors to track and read the user's movements, similarly to Microsoft's Xbox Kinect system, along with functionality to transfer content from a smaller screen, such as smartphone or tablet computer, to a larger screen.

Apple has so far taken only a tentative approach to TV, with the Apple TV product - often described by Jobs as "just a hobby" - selling only around 2m units since March 2010, compared with the more than 40m iPads shifted by the firm.

But it is thought that the living room is the California firm's next big area to revolutionise with its consumer products, potentially providing an integrated entertainment experience across its various devices.

Should Apple go ahead with offering branded flat panel TV sets, the company would need to secure partnerships with broadcasters, movie studios and other providers to offer content to users.

Sterne Agee analyst Shaw Wu wrote in a note to investors that Apple intends to offer content subscriptions with live channel packages tailored to each user's tastes.

"We continue to hear what Apple would love to do is offer users the ability to choose their own customised programming, i.e. whichever channels/shows they want for a monthly subscription fee," he said.

"Today, iTunes has a rich library of movies and TV shows but it is mostly for downloads and only movies are available for rentals. What's missing is live broadcast television."

Wu also said that Apple will most likely continue to offer its Apple TV product to avoid missing out on customers who don't want to buy a new television set.

Meanwhile, Apple is understood to be readying various other next-generation products, including a bigger iPhone and thicker iPad scheduled for launch next year.