The lesson here is to never argue more than you have to. “[T]he doctrine of prosecution history estoppel prevents a patent owner from recapturing through the doctrine of equivalents subject matter surrendered [e.g., by attorney argument during prosecution] to acquire the patent.” That being said, the patentee here seems to have lost mainly because of an overzealous suit that should never have been brought in the first place.
Background / Facts: The patent here is titled “Book Holder” and the specification describes the invention as “a removable book holder assembly for use by a person in a protective or mobile structure such as a car seat, wheelchair, walker, or stroller.” In this regard, the lone claim recites that “the book holder is removably attached,” and during prosecution it was argued in response to an initial rejection that the claim was neither anticipated nor obvious because “the use of adjustable, resilient clip arms on the clasp for clasping the book holder to the movable vehicle providing quick removal without tools … is not obvious in light of the prior art.” Nevertheless, the patentee has sued Verifone for infringement of its mounts for electronic display screens, used in New York City taxi cabs, despite the fact that it is not disputed that Verifone’s mounts are “riveted in place to the taxi’s partition or seat” and are not of the removable nature described by the claim.
Issue(s): Whether the permanent rivet attachments of the Verifone mounts are equivalent to the removably attached clips of the type claimed.
Holding(s): No. Without touching the equivalency determination directly, the court fixated on the fact that “[d]uring prosecution, in response to a prior art rejection, Ottah emphasized that the patentability of the ’840 patent’s claim was based on the removable nature of the mount. He cannot now, under the doctrine of equivalents, seek to broaden the scope of his claim to include mounts that are fixed as well as those that are removable.”