March 12, 2008 | By Emily Berger

Reexamination Improves Patent Quality: A Look at the Latest USPTO Filing Data

Coauthored by Policy Intern Raeanne Young

The latest statistics [PDF] from the Patent and Trademark Office prove what EFF has been saying for years: third party challenges to patent validity provide an invaluable check on improper and overbroad patents. According to these records, in the 25 years since ex parte reexamination became possible, the PTO has granted the vast majority of reexamination requests. In other words, the PTO found that the third party challenge raised substantial new questions of patentability. Thus, rather than overburdening the examiners, reexamination requests are helping the PTO separate the wheat from the chaff, fix mistakes and meet its stated goal: to promote innovation.

Since the start of ex parte reexamination in 1981, there have been over nine thousand requests that the PTO revisit issued patents, averaging over five hundred annually in recent years. From 1981 through the end of 2007, the Office of the Patent Commissioner has granted over ninety percent of these ex parte reexamination requests. Out of the eight thousand requests that have been granted since the start of ex parte reexamination, six thousand and sixty resulted in a narrowing of claims. In other words, the PTO grants 92% of the reexamination requests it receives, and in 3 out of 4 of those cases, the requests are having a substantial effect on the claims.

This data demonstrates how reexamination can help limit the impact of illegitimate patents on the public domain. With the PTO reworking 3 out of 4 patents in reexamination and often revoking the entire patent, these proceedings are clearly essential to the PTO’s continuing ability to pursue high patent quality.

Unfortunately, the success of ex parte reexamination proceedings is being overlooked by the latest draft of S.1145, the Patent Reform Act of 2007, which is raising some serious concerns about the ability of the PTO to continue to ensure good patent quality. As we recently reported, the latest draft of the Patent Reform Act of 2007 replaces the current reexamination processes with an inadequate form of post-grant review and places undue restrictions on third party participation. This portion of the Act could essentially eliminate important public interest projects, such as EFF's Patent Busting Project which uses inter and ex parte reexamination proceedings to challenge patents that endanger the public domain. The PTO recently granted EFF's fifth patent reexamination request.

EFF is working to gather more information about recent patent reexamination proceedings and other public interest efforts to control patent quality through the reexamination process. If you have information that could be helpful, please contact To keep third party reexamination as a component of the Patent Reform Act, take action now.

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