Microsofts FAT Patent Under Review

UPDATED: Granting a request by the nonprofit Public Patent Foundation, the U.S. Patent and Trademark Office will re-examine the patent the company holds on the file allocation table file system-a move that

In a move that could ultimately deal a heavy blow to Microsofts intellectual property rights, the U.S. Patent and Trademark Office will re-examine the patent the company holds on the FAT (file allocation table) file system, a format used for the interchange of media between computers and digital devices.

The request to re-examine Microsoft Corp.s FAT patent was made in April by the Public Patent Foundation (Pubpat), a nonprofit public-service organization that describes its mission as "protecting the public from the harms caused by wrongly issued patents and unsound patent policy."

In its decision, here in PDF form, to re-examine the FAT patent, the patent office said, "A substantial new issue of patentability, which has not been previously addressed, has been raised. ... In particular, storing a checksum of the short filename in the directory entry."

Microsoft now has the opportunity to make an opening statement to the patent office within two months, to which Pubpat has the right to make a response.

If Microsoft makes such a statement, the patent office will then determine whether the patent, No. 5,579,517, is indeed invalid in light of the new questions the foundation raised in its request.

"The patent claims methods implemented by computer systems for storing both long and short filenames for a file and then accessing the short file name," Pubpat said in its April filing requesting the re-examination, here in PDF form.

"These methods are incorporated into Microsofts FAT file system, originally created in the mid-1970s, which is used to interchange media amongst the vast majority of computers and digital devices in use today," Pubpat said.

"Unfortunately, Microsoft is using its control over the interchange of digital media to aid its ongoing effort to deter competition from free and open-source software. Specifically, Microsoft does not offer licenses to the 517 patent for use in free software.

"As such, the 517 patent stands as a potential impediment to the development and use of free software because free software users are denied the ability to interchange media with machines or devices running Microsoft-owned or -licensed software."

But the Patent Office said the issue of "significant public harm" and the allegations that the patent "stands as a potential impediment to the development and use of free software" will not be addressed in the re-examination, as they are outside its scope.

/zimages/6/28571.gifMicrosoft recently patented the use of a variety of clicks on a single button on a PDA. Click here to read more.

David Kaefer, director of Microsofts Intellectual Property and Licensing Group, remained upbeat, telling eWEEK that Microsoft has already licensed its FAT specification and patents to help improve interoperability.

The U.S. patent office often grants re-examination requests, Kaefer said, adding that such requests "provide an important mechanism to assure high levels of patent quality."

/zimages/6/28571.gifClick here to read more about Microsofts strategy to assemble a hefty arsenal of patents.

But Pubpat officials are hopeful that the re-examination will be successful. "Third party requests for re-examination, like the one filed by us, are successful in having the subject patent either narrowed or completely revoked roughly 70 percent of the time," Pubpat said in a statement released Friday

"We are obviously very pleased with the patent offices decision to grant our request to re-examine Microsofts FAT patent," said Dan Ravicher, Pubpats executive director and founder. "This is the first step toward ending the harm being caused to the public by this patent that should have never been issued."

But Microsoft in December debuted a new, streamlined intellectual-property (IP) licensing strategy with the announcement that it was offering its FAT file system and ClearType font-rendering technologies—for a fee—to any interested licensees.

Editors Note: This story was updated to include comment from Microsoft officials.

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