Lighting Defense Group LLC v. Shanghai Sansi Electronic Engineering Company Limited
2:22-cv-01476
D. Ariz.Mar 11, 2025Background
- This case involves patent infringement claims by Lighting Defense Group LLC ("LDG") against SANSI entities related to LED lighting products.
- LDG alleged infringement of four patents concerning heat management technology in mountable LED light fixtures.
- The parties used representative product groupings and agreed that proof as to a representative product within a group would apply to the group as a whole for litigation purposes.
- The Court's Case Management Order required LDG to disclose specific alleged infringement theories, accused products, and how each claim was satisfied, with amendments permitted only for good cause and by court order.
- After the deadline for amending contentions, LDG attempted to serve a second amended set of infringement contentions and then relied on these in its expert report by Dr. Katona, even though leave to amend was denied.
- SANSI moved to strike portions of the expert report that contained new theories or coverage of new patents and products, arguing these exceeded the scope of operative infringement contentions.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Whether expert can assert new infringement theories not disclosed in operative contentions | Expert report does not introduce new theories; overlap and prior notice existed | Expert report introduces new infringement theories not properly disclosed | New theories not in operative contentions are stricken |
| Whether expert can newly allege previously identified products infringe additional patents | All representative products infringe similar claims due to feature overlap | Expert report improperly expands coverage to patents not previously charted | Opinions on new patent-product combinations are stricken |
| Use of newly discovered SKUs and ASINs to expand accused products/groupings | Adding SKUs/ASINs was a clarification (not expansion) of accused products | Listing additional SKUs/ASINs after deadline is improper expansion | Court rejects justification; expansion not allowed |
| Whether new "multi-member" and "multi-channel" infringement theories are properly disclosed | Figures/arrows in operative charts indicated the theory was disclosed | Charts used singular language—multi-member/channel theories are new | New multi-member/channel theories are stricken |
Key Cases Cited
- O2 Micro Int'l Ltd. v. Monolithic Power Sys., Inc., 467 F.3d 1355 (Fed. Cir. 2006) (infringement contentions must crystallize theories early and avoid "shifting sands").
- Genentech, Inc. v. Amgen, Inc., 289 F.3d 761 (Fed. Cir. 2002) (prohibiting shifting infringement theories after claim construction).
- AntiCancer, Inc. v. Pfizer, Inc., 769 F.3d 1323 (Fed. Cir. 2014) (contentions need not include proof, just theory).
- Keranos, LLC v. Silicon Storage Tech., Inc., 797 F.3d 1025 (Fed. Cir. 2015) (district courts have broad discretion to manage and enforce local patent rules).