The US Court of Appeals for the Federal Circuit upheld a district court’s claim construction and jury instructions but reversed a premature judgment as a matter of law (JMOL) on obviousness and an imprecise damages award. Cyntec Company, Ltd. v. Chilisin Electronics. Corp., Case No. 22-1873 (Fed. Cir. Oct. 16, 2023) (Moore, Stoll, Cunningham, JJ)

Cyntec sued Chilisin for willful infringement of two patents related to molded chokes, which are component parts in batteries and power supplies. Four events at trial led to this appeal. First, the district court construed the disputed “by means of” term by its plain meaning but also instructed the jury that when a result occurs “by means of” a factor, that factor “has an impact on”—but may not be the “only potential cause” of—the result. Second, Chilisin presented invalidity evidence, arguing that the asserted claims were obvious by one prior art reference in light of another.

Before Chilisin could cross-examine Cyntec’s rebuttal expert, the district court granted Cyntec’s JMOL, finding the patents not obvious. In the third event that led to the appeal, Cyntec presented a market-share lost profits theory of damages based on expert testimony. Chilisin unsuccessfully moved to exclude the testimony as being speculative and unreliable. The jury awarded more than $1.8 million in damages and the district court subsequently granted enhanced damages totaling more than $5.5 million. As for the fourth event, Chilisin unsuccessfully moved for JMOL and a new trial on multiple issues. Chilisin then appealed.

The Federal Circuit reviewed three issues on appeal

1. The nonobviousness JMOL

2. The infringement findings

3. The damages award.

Starting with nonobviousness, the Federal Circuit reversed the JMOL and remanded. While obviousness is ultimately a legal question, it relies on “numerous underlying factual findings,” including the scope/content/differences of prior art, the skill level of a person of ordinary skill in the art and objective indicia of nonobviousness such as commercial success. The Court found Chilisin had presented enough evidence to allow a jury to find the asserted claims obvious in light of the two prior art references presented. The Federal Circuit also analyzed the district court’s reasoning regarding the prior art and found that its “conclusions are either insufficient to support JMOL or unsupported by the evidence.” Thus, it was improper to withhold a partial fact issue from the jury.

Next, the Federal Circuit analyzed the infringement issue, dividing the analysis into the district court’s claim construction and jury instructions, and the jury’s infringement finding. Chilisin argued that the disputed term “by means of” should signal but-for causation, meaning the factor must cause the result. The Court agreed that this was one possible reading, but because the claim language did not read “by exclusive/primary means” or something similar, the disputed term could also encompass “mere contribution.” The Federal Circuit cited to the specification in support of its claim interpretation and ultimately upheld the district court’s claim construction and the consistent jury instructions. The Court rejected Chilisin’s argument that there was insufficient evidence of infringement, concluding that Cyntec had provided sufficient evidence to allow the jury to reach that finding.

Finally, the Federal Circuit addressed damages. Chilisin had filed a Daubert motion to exclude Cyntec’s damages expert’s testimony. The Court stated that district courts serve a “gatekeeper” role to ensure all admitted evidence is not just relevant, but reliable. Here, the Court found that Cyntec’s damages expert’s testimony was speculative. For instance, he used US Securities and Exchange Commission (SEC) filings from customers who purchased the allegedly infringing products to determine a customer company’s revenues to calculate Cyntec’s lost profits, but the filings clearly included irrelevant products that did not contain chokes. While Cyntec argued that he had corroborated his results against third-party data, he had done so for only six of the 27 customers in his calculations. Based on the jury’s dependency on this unreliable testimony, the Court vacated the damages award.

Practice Note: Parties that lose on JMOL motions should preserve the issues and consider appeals. All parties should vet their damages experts and critically test not just their theories, but the input data used in their calculations.