Register | Login
Intellectual Property Today
RFC Express - New IP Lawsuits

Claim Changes in Reexamination and Reissue

By Matthew C. Phillips and Kevin B. Laurence of Stoel Rives LLP

Kevin Laurence and Matt Phillips are partners at Stoel Rives LLP.  They authored a treatise titled “Patent Reexamination and Reissue Practice,” from which they teach a multi-day course for Patent Resources Group.  Kevin’s technical focus is pharmaceuticals, chemistry, and medical devices; Matt’s is electronics and computer technologies.  They can be reached at and

Reexamination and reissue can affect patents in a variety of ways. Most notably, a reexamined or reissued patent that has different claims, either by amendment to claims originally present or by addition of new claims, may or may not have retroactive effect back to the original issue date of the patent. Such claim changes may or may not also give rise to intervening rights, thereby limiting the patent owner's ability to prevent certain future acts that would otherwise be infringement but for the reexamination or reissue proceeding. This article discusses the circumstances under which past liability may be extinguished and intervening patent rights are typically created in the reexamination or reissue process.


The threshold issue in determining pre-certificate or pre-reissuance liability arises under 35 U.S.C. § 252. The statutory test is whether the claims, as amended in reexamination or reissue, are "substantially identical" to the claims in effect prior to the issuance of a reexamination certificate or reissuance of a patent.1 If so, then it is as if the reexamination or reissue proceeding never occurred, and upon a finding of infringement of a valid claim and in the absence of another defense, the infringer will be fully liable for all its actionable infringement before and after the reexami...

To view the complete article you must be logged in
Login Now

Not A Member Yet? Sign Up For A Free 10 Day Trial Account!

  © Copyright 2010 Intellectual Property Today — Designed By
Download Adobe Reader for free