Federal Circuit Holds District Court Abused Its Discretion by Excluding an Authenticating Witness

JIAXING SUPER LIGHTING ELECTRIC APPLIANCE, CO. v. CH LIGHTING TECHNOLOGY CO., LTD.

Before Dyk, Chen, and Hughes. Appeal from the United States District Court for the Western District of Texas.

Summary: The Federal Circuit reversed the district court’s JMOL of no on-sale bar after holding the district court abused its discretion in excluding a witness who would have authenticated documents on that issue.

Super Lighting sued CH Lighting alleging infringement of three patents related to LED tube lamps, including two patents related to purported structural improvements in LED tube lamps (the “tube patents”). Before trial, CH Lighting conceded infringement of the tube patents. At trial, the district court granted Super Lighting’s motions (1) to exclude evidence relating to invalidity of the tube patents and, subsequently, (2) for judgment as a matter of law (“JMOL”) that the tube patents were not invalid on the ground of an on-sale bar. The jury awarded damages for infringement, and CH Lighting appealed.

The Federal Circuit reversed the district court’s grant of JMOL that the tube patents were not invalid. The court held that the district court abused its discretion in excluding CH Lighting’s witness who would have authenticated documents regarding an on-sale bar. It noted the district court did not identify any rule or order requiring parties to identify in advance which witnesses would authenticate documents, and that there was no such requirement under any federal or local rule. The Federal Circuit also ruled the district court should have conducted a more exacting gatekeeping analysis of the testimony of Super Lighting’s damages expert. It directed the district court to assess the reliability of that testimony under the court’s recent en banc decision in EcoFactor, Inc. v. Google LLC, 137 F.4th 1333 (Fed. Cir. 2025), which noted that “[a]n absence of reviewable reasoning may be sufficient grounds for this court to conclude the district court abused its discretion.” Accordingly, the Federal Circuit vacated the jury’s award of damages and remanded for a new trial on the validity of the tube patents and damages.

Editor: Sean Murray