According to the U.S. Patent and Trademark Office, the title transfer was recorded on March 17, 2010, five days after Apple began pre-selling its first iPad.

CNN: Apple loses right to iPhone name in...

Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title.

FORBES: Software Patents and Judicial Activism

Details of an immersive video games display system that projects images of the title's environment around a player's room have been revealed in a US patent belonging to Microsoft.

BBC: Microsoft patent diagram