Terminal Disclaimer Alone Not Admission That Continuation Patent Is Patentably Indistinct From Parent Patent

  • April 1, 2017
SimpleAir, Inc. v. Google LLC

In SimpleAir, the Federal Circuit held that filing a terminal disclaimer during the prosecution of a continuation patent application does not give rise to a presumption that the continuation is patentably indistinct from the corresponding parent application. Thus, a final judgment entered against a parent patent did not foreclose litigation of a child patent under the doctrine of claim preclusion.

SimpleAir was the owner of a family of patents directed to push notification technology. The family includes a parent patent and continuation patents that claim priority from the parent application. Each patent application within the family shared a common specification. During prosecution of the family of patents, SimpleAir filed terminal disclaimers in each continuation application to overcome obviousness-type double patenting rejections in view of the parent patent.

SimpleAir instituted a series of lawsuits against Google. In each suit, SimpleAir alleged infringement of a different group of patents from the family of patents. After three unsuccessful lawsuits, the district court dismissed a fourth SimpleAir lawsuit as being barred by claim preclusion. Specifically, the district court found that the asserted patents involved the same cause of action as the prior lawsuits because the terminal disclaimers indicated that the patents were not patentably distinct. SimpleAir appealed.

The doctrine of claim preclusion posits that a judgment on the merits in a prior suit involving the same parties or their privies bars a second suit based on the same cause of action. When determining whether two patent cases present the same cause of action, the Federal Circuit looks at whether there is a substantial overlap in the essential transactional facts, such as the patents asserted and the accused activity. The test is pragmatic, not mathematical, and preclusion will not be foreclosed because a different patent is asserted in the later action if the claims at issue are essentially the same.

The Federal Circuit vacated the district court’s order, holding that the record was not sufficient to sustain the district court’s holding. The court reasoned that SimpleAir’s decision to file a terminal disclaimer was relevant to the inquiry, but was not an admission by itself that the asserted patents were patentably indistinct from the other litigated patents. Rather, claim preclusion required a more detailed analysis as to whether the claims were essentially the same. Since the district court did not specifically compare the disputed claims, the Federal Circuit remanded the case for further proceedings.

Key Takeaway:

A court may not presume that lawsuits asserting a parent patent and a terminally-disclaimed continuation patent necessarily constitute the same cause of action. Nevertheless, the filing of a terminal disclaimer may be relevant to a court’s determination of whether a disclaimed continuation patent lacks a patentable distinction over the parent patent.


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