Microsoft's FAT Patents Upheld

Ending a two-year battle over the FAT file system, the U.S. Patent and Trademark Office has reversed a non-final ruling from October and upheld Microsoft's patents on the technology. Despite the prior setbacks, Microsoft had remained steadfast that it would be victorious all along.

In June of 2004, the USPTO agreed to review the patent after questions arose surrounding its validity. A group known as the Public Patent Foundation disputed Microsoft's claims to FAT in April 2004, saying it had become ubiquitous as a format and found in many devices.

After an initial rejection of the patents in September 2004, the USPTO rejected two patents related to long file names in October 2005. At the time, Microsoft noted that the non-final rejections were based on issues with the inventor named on the patent application, not claims of prior art from PubPat.

"None of the prior art submitted by the Public Patent Foundation stood up under examination. The issues that have come up in these reexaminations have nothing to do with non-Microsoft prior art," David Kaefer, Director of Business Development and IP Licensing, explained in October.

Microsoft has now prevailed and the USPTO is in the process of issuing a "patent re-examination certificate." The company could theoretically seek royalties from companies utilize FAT, including Linux vendors and memory stick manufacturers. Lexar has already licensed the technology from Microsoft.

Saying Microsoft was pleased with Tuesday's decision, Kaefer added that, "This result underscores the validity of these patents but also the importance of allowing third parties to request re-examinations."