Carl Zeiss X-Ray Microscopy, Inc. v. Sigray, Inc.

Background

Carl Zeiss X-Ray Microscopy, Inc. sued Sigray, Inc. for patent infringement and trade secret misappropriation. Zeiss alleged that Sigray’s Prisma and TriLambda x-ray microscopes infringed two patents and that Sigray misappropriated trade secrets related to x-ray microscopy. The opinion notes that the court had previously held at summary judgment that the accused products infringed the asserted patent claims discussed there.

Fact discovery closed on February 16, 2023, and expert discovery closed on July 27, 2023. After Zeiss served its initial and reply expert reports, Sigray produced documents identifying additional sales of products that Zeiss claimed were accused products. Zeiss moved for permission to serve supplemental reports from its liability expert, Dr. Gregory Denbeaux, and damages expert, Ms. Kimberly Schenk. The proposed reports would address the additional sales using the same infringement theories and lost-profits analysis as the original reports.

Sigray did not oppose Zeiss’s request for supplemental reports, but sought to reopen fact and expert discovery in connection with them.

Court’s analysis

Federal Rule of Civil Procedure 26(e) requires timely supplementation when a party learns that an expert disclosure is materially incomplete or incorrect. The court explained that this duty can continue after discovery closes and generally requires supplementation by the deadline for pretrial disclosures, unless the court orders otherwise. A supplemental report may correct inaccuracies or fill gaps based on information unavailable when the original report was prepared, but may not introduce significantly different theories, new opinions, or new rationales.

The court found that Zeiss’s proposed supplementation was proper because it would only extend the experts’ existing analysis to additional sales. The court therefore held that Zeiss could serve the supplemental reports without reopening discovery. Because no trial date or pretrial-disclosure deadline had yet been set, the court stated that the usual 30-day pretrial-disclosure deadline did not determine when Zeiss had to serve the reports.

The court separately considered Sigray’s request to reopen discovery. Reopening discovery requires good cause, including diligence and whether additional discovery would likely produce relevant evidence. The court found that Sigray had shown diligence concerning expert discovery about the additional sales, but not concerning related fact discovery. The court noted that Sigray had had an opportunity during the fact-discovery period to identify customer witnesses concerning those sales and had not done so.

The court nevertheless found good cause to permit limited additional expert discovery. It authorized depositions of Zeiss’s two experts and supplemental rebuttal reports from Sigray’s experts, all limited to the additional sales and the new material in Zeiss’s supplemental reports.

Ruling and schedule

The court granted Zeiss’s motion for leave to serve supplemental expert reports. Zeiss was required to serve those reports by April 18, 2025.

The court also granted Sigray leave to conduct supplemental depositions of Dr. Denbeaux and Ms. Schenk by May 2, 2025. Sigray could serve rebuttal reports by May 16, 2025, and its experts’ rebuttal depositions had to be completed by May 30, 2025. Each party’s depositions were limited to two hours.

The court further ordered the parties to submit a joint status report by April 11, 2025, addressing whether a trial beginning at the end of August was feasible and, if so, proposing pretrial-briefing deadlines. If that timing was not feasible, the report had to provide updated trial availability.