Japanese electronics firm Sony formally joined the tablet fray this week, with two Android tablets, likely paving the way for a new flurry of lawsuits over form factor.

The more familiar looking S and the clamshell type P model will go on sale in Japan, the US and Europe from September 17. Both tablets are equipped with Android 3.0, wifi and 3G/4G connectivity, while the S has a 9.4-inch display and the P has two 5.5-inch displays that can be folded and used together as one large screen.

Playing on its extensive tech portfolio, through Qriocity music and video services, Sony tablet users can access rich video and music content and the PlayStation Suite of first generation PlayStation titles.

Meanwhile, Samsung, which is lately getting the business end of Apple’s legal stick has come out with a new device it describes as “a new category of product”.

The Galaxy Note has a 5.3” display, putting it somewhere between a smartphone and a tablet. Under the hood is a 1.4GHz dual-core processor and HSPA+ and LTE connectivity. Although it has a touch screen, the Note features pen-input technology, called the S Pen, which can be used for accurate sketching and artwork, as well as a multimedia application designed to record all forms of user-created content and convert them to a ‘memo’, to be edited, annotated and shared.

Samsung said it plans to release the S Pen SDK allowing app developers to create new applications and services incorporating the pen functionality.