Microsoft FAT Patent
In April 2004, the Public Patent Foundation filed a formal request with the United States Patent and Trademark Office to revoke Microsoft Corporation's patent on the FAT File System, touted by Microsoft as being "the ubiquitous format used for interchange of media between computers, and, since the advent of inexpensive, removable flash memory, also between digital devices." In its filing, PUBPAT submitted previously unseen prior art showing the patent, which issued in November 1996 and is not otherwise due to expire until 2013, was obvious and, as such, should have never been granted. The PTO granted PUBPAT's request in June 2004 and provisionally rejected the patent in September 2004. In response to the rejection, Microsoft made amendments to the patent's claims. The PTO proceeded to allow the amended form of the patent. PUBPAT had no right to appeal that decision.
- PUBPAT's Request for Reexamination of Microsoft's FAT Patent (PDF; 547KB)
- Patent Office's Order Granting PUBPAT's Request for Reexamination of Microsoft FAT Patent (PDF; 1.2MB)
- Patent Office's Office Action Rejecting Microsoft FAT Patent (PDF; 592KB)
- September 30, 2004: AT PUBPAT'S REQUEST, PATENT OFFICE REJECTS MICROSOFT'S FAT PATENT: Government Relies Heavily on Evidence Submitted by PUBPAT
- June 10, 2004: MICROSOFT FAT PATENT TO BE REEXAMINED AT PUBPAT'S REQUEST: Patent Office Agrees There is a "Substantial Question" Regarding FAT Patent's Validity
- April 15, 2004: PUBPAT CHALLENGES MICROSOFT PATENT TO PROTECT COMPETITION IN SOFTWARE MARKETS: Patent Office Shown New Evidence Proving FAT Technology Was Obvious