Scott Daniels | February 25, 2010
A third party typically files a request for reexamination with the goal of invalidating the patent. But even if the patent survives and the PTO issues a Reexamination Certificate, the third party requester may benefit if the patent claims are amended during reexamination.
If the patentee makes a substantive change to a patent claim during reexamination, the patent owner can recover damages only from the date the Reexamination Certificate was issued. To determine whether a change is substantive, the Court determines whether the scope of the claim has changed. Laitram Corp. v. NEC Corp., 163 F.3d 1342, 1346 (Fed. Cir. 1998).
This principle was demonstrated anew this past week in Yoon Kim v. Earthgrains (Sarah Lee), 2010 U.S. Dist. LEXIS 14815 (N.D. Ill. February 18, 2010).
Yoon Kim’s patent claimed a composition useful in bread-making as a replacement for potassium bromate, the claimed composition “consisting essentially of” a series of recited ingredients. A third party requested reexamination asserting that the claims were invalid over certain prior art references.
The PTO granted the request and rejected the claims over the cited art. After prolonged prosecution, Yoon Kim amended its main claim by replacing “consisting essentially of” with “consisting of,” as well as by adding the limitation of a dependent claim. The examiner agreed that the amended claims were valid over the cited prior art, and a Reexamination Certificate issued on March 31, 2009.
In litigation that had been pending during the reexamination, the accused infringer moved for partial summary judgment that the main claim had been substantively amended in the reexamination and that any damages awarded should be limited to sales during the period starting March 31, 2009, the date of the certificate. The trial judge agreed that the claims had been narrowed and granted the motion limiting any damage amount that might be awarded in a later judgment against the accused infringer.
In many cases, this possibility of limiting damages to the period following issuance of the reexamination certificate, affords the accused infringer the time needed to redesign its accused product and perhaps avoid liability altogether.