Background
SimpleAir, Inc. owns a family of patents directed to systems and methods for broadcasting real-time information, such as news and data updates, over wireless networks to mobile devices. The family includes a parent patent and multiple continuation patents, many of which were filed with terminal disclaimers during prosecution to overcome obviousness-type double patenting rejections.
SimpleAir brought successive patent infringement lawsuits against Google, asserting different patents from the same family in each suit. After SimpleAir lost its first lawsuit (asserting the parent patent) on invalidity grounds, Google argued in the subsequent suit that claim preclusion barred SimpleAir from asserting the continuation patents. The district court agreed, reasoning that because SimpleAir had filed terminal disclaimers in the continuation patents, there was a presumption those patents were “patentably indistinct” from the parent—and thus within the scope of the earlier judgment.
SimpleAir appealed, arguing that a terminal disclaimer is not an admission that the continuation’s claims are the same as the parent, and that the district court had not actually compared the claims.
The Court’s Holding
The Federal Circuit vacated and remanded. The court held that a terminal disclaimer does not give rise to a presumption that a continuation patent is patentably indistinct from its parent. While a terminal disclaimer is strong evidence—because both the examiner and the applicant conceded during prosecution that the continuation lacked a patentable distinction from the parent—it is not conclusive proof of patentable indistinctness. Other circumstances could cause an applicant to file a terminal disclaimer even when the claims are actually distinguishable from the parent.
For claim preclusion to bar assertion of a continuation patent after judgment on the parent, the claims at issue in both suits must be “essentially the same” in scope. The standard for determining whether claims are essentially the same requires an actual comparison of the claims themselves—not just a procedural inference drawn from patent prosecution history. Because the district court had relied on the terminal disclaimer presumption rather than comparing the specific claims, its preclusion ruling could not stand. The case was remanded for the required claim-by-claim analysis.
Key Takeaways
- A terminal disclaimer filed during prosecution is strong evidence that continuation claims are not patentably distinct from the parent, but it does not create a binding legal presumption of patentable indistinctness for claim preclusion purposes.
- Claim preclusion between a parent patent and continuation patents requires an actual comparison of the claims in both suits to determine whether they are “essentially the same” in scope.
- Patent owners with continuation families can assert different continuation patents in successive lawsuits without being automatically barred by claim preclusion, as long as the continuation claims are meaningfully different from the previously adjudicated parent claims.
- For defendants, establishing claim preclusion in multi-patent family litigation requires specific claim-by-claim analysis—shortcuts based on prosecution history alone are insufficient.
Why It Matters
Patent families—where inventors file a series of continuation applications to obtain broader or differently-scoped claims—are common across all technology sectors. The question of when a judgment against one patent in a family bars assertion of other family patents is frequently litigated and has significant consequences for both patent enforcement and invalidity strategy.
SimpleAir v. Google established that defendants cannot use a terminal disclaimer as a silver bullet to eliminate an entire continuation family after winning on one patent. This protects patent owners’ legitimate ability to use the continuation process to obtain claims tailored to specific products and time periods. At the same time, the decision clarifies that some continuations—those whose claims are truly indistinct from the parent—will still be barred by claim preclusion once the parent is adjudicated. The key is actual comparison, not procedural shortcuts.