Sua Sponte Finding of Invalidity in Sonos v. Google Creates Confusion at Federal Circuit

In an article for IAM, Sterne Kessler Directors Paul Ainsworth and Joseph Kim examined the sua sponte decision that found a patent invalid in the U.S. Court of Appeals for the Federal Circuit’s consideration of Sonos v. Google.

The appeal came from a decision by the U.S. District Court for the Northern District of California to throw out a $32.5 million jury verdict in favor of Sonos in their dispute with Google over connected speaker technology. The decision vacates an earlier grant of summary judgment of infringement, and held the patents unenforceable for prosecution laches and invalid for a lack of written description and for anticipation, since the addition of new matter in 2019 made the accused Google products prior art.

This move appeared to concern the Federal Circuit panel during the oral argument. The panel questioned the parties on the procedural missteps that preceded this decision.

The procedural history of the case is important to understand. The district court ordered both parties to participate in its expedited “patent showdown” procedure. The “patent showdown” required each party to select and exchange a single asserted claim and file cross motions for summary judgment of their respective claims.

As described by Ainsworth and Kim, “The patent showdown resulted in Sonos moving for summary judgment of infringement and Google moving for summary judgment of noninfringement and lack of written description. Google argued that Sonos added new matter in 2019 through a claim amendment to an application claiming priority to a non-provisional application filed more than a decade earlier in 2007 and a provisional application filed in 2006. Google pointed out that the specification did not disclose that a zone player may be added to two zone scenes at the same time (overlapping zone scenes). In July 2022, the district court granted summary judgment of infringement and denied Google’s summary judgment motion, concluding that the challenged claims had adequate written description as a matter of law.”

At the May 2023 trial however, an admission from one of the inventors at Sonos eroded the early victory for the company. The inventor testified that Sonos added a new disclosure to the specification of one of its patents in 2019, which allowed the company to add claim limitations that ensnared Google’s accused products.

As a result, “The admission promoted the district court to reconsider its earlier summary judgment ruling on the adequacy of the patent’s written description. The court ordered the parties not to present the issue to the jury and instead ruled that it would be decided during post-verdict proceedings. The court threw out the jury verdict and held the Sonos patent unenforceable for prosecution laches and invalid because a subsequent claim amendment directed to overlapping zone scenes lacked written description in the priority application and, consequently, the claims were anticipated. In so doing, the court found that Sonos had engaged in a continuation strategy to keep the patent family alive for more than 13 years to capture later released products on the market.”

On appeal, Sonos argued that Google had forfeited its new matter argument, saying it did not raise it at trial. Google disputed this account, stating that the district court initially found that written description requirement was met as a matter of the law. Google contended that it could not have presented that issue to the jury at trial.

Back at the Federal Circuit, Sonos and Google’s interpretation of the district court’s decision greatly differed. The Federal Circuit court panel questioned how the two companies could have such a “fundamental disconnect” on their understanding of the summary judgment decision. Both parties then pointed to the other for not seeking clarification on what the district court had decided.

“The Federal Circuit has been critical in the past when a district court raises invalidity defenses on its own motion,” Ainsworth and Kim stated, “In Astellas Pharma Inc. v. Sandoz Inc., the Federal Circuit reversed a decision from the District of Delaware where the court had held the asserted patent invalid under Section 101 even though the defendant had not presented that argument at trial. The Sonos v. Google case presents similar concerns. For practitioners, this case may provide another cautionary tale for defending a district court’s sua sponte finding of invalidity.”