When preparing patent infringement claim charts under the local patent rules, a plaintiff will often attempt to provide a single claim chart that applies to many similar products rather than provide a claim chart for each and every accused product.  The courts interpreting the local patent rules have differed on whether such representative claim charts are proper.  Patent litigants should be well informed on this issue because a court’s interpretation of the local patent rule is often dispositive.

In Voxpath RS, LLC v. LG Electronics U.S.A., Inc. (.pdf), the Court ruled that a single infringement claim chart representative of many similar accused products was improper and disallowed the case to proceed on those similar accused products.  In its ruling, the Court did not accept the plaintiff’s reliance on previous court rulings from the Eastern District of Texas and the Northern District of California that have allowed for the disclosure of a single chart for multiple accused products where “products likely operate in a manner reasonable similar to the infringement theory described in [plaintiff's preliminary infringement contentions].”  See, Honeywell Int’l, Inc. v. Acer America Corp., 655 F.Supp.2d 650, 657 (E.D.Tex. 2008).  Instead, the Court emphasized that the local patent rules require a claim chart mapping out where “each infringing product (identified by model number) contains each element of the claim it infringes.”  L. Pat. R. 3.1(b)-(c))  The Court also rejected the plaintiff’s argument that it would be unduly burdensome to create a separate chart for each accused product, especially given the plaintiff’s financial status.  Finally, the Court was persuaded by the fact that the plaintiff did not explain how the allegedly similar products were so similar from a technology standpoint that a single claim chart was justified.

Key Takeaway:

A patent owner should not assume that a single claim chart representative of similar accused products will be found sufficient under the local patent rules.  Instead, if such a representative claim chart is relied upon, a plaintiff should be prepared to also disclose how the products are similar or identicial from a technology standpoint to justify a single claim chart under the local patent rules.