FAT Patent Falls Short of Non-Obvious

A search for FAT in news.google.com today will bring up over 60 articles relating to the PTO’s recent preliminary rejection of Microsofts FAT patent. In an ex parte reexamination instigated by the Public Patent Foundation, the PTO declared claims 1-4 of U.S. patent no. 5,579,517 invalid as anticipated by prior art. Commentators are calling this the rediscovery of 35 U.S.C. 103(a), which prohibits patents on inventions that would have been obvious to a person of ordinary skill in the relevant art at the time the invention was made. Open source programmers, who feared the patent might be used to claim royalties against Linux, may be heaving a preliminary sigh of relief, but FAT users probably shouldn’t rip up their licensing agreements just yet. The FAT license covers a portfolio of four patented Microsoft technologies and several others with patents pending.

FAT denotes “File Application Table” and refers to a data structure that tells higher-level systems how to assemble scattered strings of bits in a storage device into a single conveniently named file. The rejected claims refer to a system of mixing DOS file names with longer and more descriptive file names. The file format is used to store files not just on computers, but also on removable flash memory cards such as those in digital cameras. It is also used in the open source software Samba, that lets Linux and Unix computers exchange data with Windows computers, and allows Linux users to read and write files on Windows hard drives. In 2003 Microsoft began attempting to collect royalties of 25 cents per device, maxing out at 25,000 dollars a year, from digital camera manufacturers using the technology in flash cards.

The patent was originally issued to Microsoft in 1996, but the company claims it developed the technology as early at 1976. If the technology had been publicly used or sold in the United States more than one year prior to the application for the patent, it would also be unpatentable under 35 U.S.C. 102(b). But, software was held unpatentable, as expressions of naturally occurring algorithms, until the State Street Bank decision in 1998. The ex parte reexamination of the patent was instigated by an organization known as the Public Patent Foundation.

The Public Patent Foundation declares, “Wrongly issued patents and unsound patent policy harm the public…by making things more expensive, if not impossible to afford, by preventing scientists from advancing technology, by unfairly prejudicing small businesses, and by restraining civil liberties and individual freedoms.” Their mission is to represent the public interest against wrongly issued patents and unsound patent policy. In April of this year the organization filed it’s formal request for reexamination and revocation of the FAT patent with the PTO, presenting significant evidence of prior art, predating the 1996 patent application. Although in the aftermath of the PTO’s preliminary rejection of the FAT patent, Microsoft spokesman announced only that the company looks forward to the opportunity to show how innovative the technology really is, PubPat notes that 70% of patents subject to reexamination instigated by third parties are either revoked or significantly narrowed.