Addressing the issue of whether the filing of a terminal disclaimer that rendered a patent unenforceable by the applicants was an error for the purposes of the reissue statute, the U.S. Court of Appeals for the Federal Circuit affirmed a ruling from the U.S. Patent and Trademark Office’s (PTO) Patent Trial and Appeal Board Board, finding that an applicant’s choice is only an error when based on a false or deficient understanding of fact or law.  In re Dinsmore, Case No. 13-1637 (Fed. Cir., June 10, 2014) (Taranto, J.).

Inventors Dinsmore and Caruso sought reissue of their patent directed to a miniature x-ray source and assigned it to twX, LLC.  During original prosecution, the examiner rejected the claims on the basis of non-statutory obviousness-type double patenting in view of an earlier patent invented by Dinsmore and assigned to another company.  The applicants submitted the PTO’s standard terminal disclaimer form, which declares that the resulting patent will only be enforceable when commonly owned with the earlier patent.  The PTO examiner withdrew the rejection and granted the patent.

A year later, the inventors sought to reissue all claims under 35 U.S.C. § 251, this time without the terminal disclaimer.  The inventors claimed that the terminal disclaimer was ineffective and invalid because it rendered the patent unenforceable, since it was not commonly owned with the earlier patent.  The reissue examiner concluded that the inventors’ voluntary and intentional filing of a terminal disclaimer did not constitute an “error” and denied the reissue application.  After the Board affirmed, the inventors appealed.

The Federal Circuit rejected the inventors’ argument that the terminal disclaimer was ineffective because it did indeed produce the intended effect of preventing enforcement of the later issued patent unless commonly owned with the earlier patent.  The Court also disagreed that the disclaimer was invalid, noting that nothing was missing that was required nor anything included that was forbidden.

As to the inventors’ position that the disclaimer was ineffective in the sense that it did not produce a patent that they themselves could enforce, the Federal Circuit concluded that that was no more than a statement of a now-regretted choice.  While the Court did agree that applicant choices can be redressed by the reissue statute, it held that such choices must be based on a false or inadequate understanding about facts or law to constitute the required error.  Since the inventors here had not shown or even alleged any misunderstanding—such as a mistaken belief that the patents were in fact commonly owned—the Court held that their decision did not constitute an error under the reissue statute.