Claim Interpretation for Expired Patents

Written by Stuart Nelson

Claim construction is a key issue in post-grant proceedings, and the application of the "broadest reasonable construction" standard is receiving increased attention. Recently in Amkor Technology, Inc. v. Tessera, Inc. (IPR2013-00242), the patent owner filed a terminal disclaimer such that the disputed patent would be effectively expired. Order, Apr. 14, 2014, p. 3. The patent owner argued that while the broadest reasonable construction applies to unexpired patents in inter partes review, claims of an expired patent should be interpreted with an analysis similar to that of a district court. Id. at 2. The patent owner now seeks "to file a motion to terminate the proceeding on the basis that the Board applied the broadest reasonable interpretation standard in the decision to institute this inter partes review." Id. at 2. It should be noted that the patent owner's position is not that the proceeding should be terminated simply because the patent is now expired, but because the proper claim construction has now changed. The petitioner opposes and the Board has requested detailed briefing on what it considers an issue of first impression. Id. at 3-4. The parties have briefed the matter, but no decision has been issued.

An unrelated case also dealt with claim construction of an expired patent, but in a different way. In Toyota Motor Corp. v. LeRoy G. Hagenbuch (IPR2013-00483), the disputed patent expired during the inter partes review proceeding just ten days after the decision to institute. Order, April 16, 2014, p. 2. During a conference call, both the petitioner and the patent owner "agreed that BRI should not be applied in the final decision" and that "the claims should be construed in a fashion similar to that used in a district court's review." Id. The Board then proceeded to construe a disputed claim term using "the proper non-BRI construction," but ultimately construed that term the same way as under the broadest reasonable interpretation. Id. at 2-3.

It will be interesting to see what the Board does with this issue in Amkor Technology, Inc. v. Tessera, Inc. as well as other cases. In the meantime, patent owners unhappy with claim interpretations during post-grant proceedings may increasingly consider the possibility of patent expiration, whether by the patent's term naturally running out or via a terminal disclaimer. However, filing a terminal disclaimer may prove risky, especially for patents with substantial term remaining, as there is no guarantee that the Board will apply a narrower construction.

For information, contact Stuart Nelson or another member of Fish’s post-grant practice.