Plans by Microsoft Corp to charge royalties on a library of patents are looking uncertain after the US Patent and Trademark Office rejected a key software patent claimed by the company.
The US Patent and Trademark Office (USPTO) rejected Microsoft’s file allocation table (FAT) patent as being unpatentable, citing existence of prior art. The USPTO said of the technologies comprising FAT: It would have been obvious to one having ordinary skill in the art at the time.
Review of the FAT patent was sparked by non-profit legal group Public Patent Foundation (PUBPAT) in April, out of concern for the implications on competition over Microsoft’s ownership of this particular patent.
PUBPAT executive director Dan Ravicher said: [FAT] is particularly important – it can deter the competition. This is a very important process, method and technology that people use to connect to Windows devices.
The FAT table provides a means of storing and retrieving files that are often scattered across a disk and held in different sizes. The FAT file system is a ubiquitous format used to exchange media, like MP3s and picture files, between Windows-based PCs and non-Windows PCs, like MP3 players or camera phones.
Microsoft last November released FAT under a commercially reasonable, non-exclusive license charging licensees $0.25 per unit up to a limit of $250,000. Microsoft yesterday claimed FAT licensing deals with Lexar Media, Rockwell International, Creative Technology and Seiko-Epson.
At the time of releasing FAT, Microsoft also released 4,000 patents and announced it would release a further 5,400 patents pending for licensing. Ravicher’s goal, though, is to challenge Microsoft on other, as yet unidentified patents.
FAT is regarded as a narrowly defined patent, potentially making it more difficult to dismiss, according to Ravicher. Success for PUBPAT over FAT would suggest the potential for success elsewhere against Microsoft in more broadly defined patents, challenging Microsoft’s ability to turn its patents catalogue into a profitable business.
Microsoft said it has 90 days in which to respond to the USPTO.