Reversing a grant of summary judgment that a patent covering synthetic mulch was invalid for not disclosing the best mode, the U.S. Court of Appeals for the Federal Circuit held that a district court improperly granted summary judgment when a genuine issue of material fact existed as to whether the best mode was disclosed in the specification. Green Edge Ent. LLC v. Rubber Mulch Etc. LLC, Case Nos. 2009-1445, -1479 (Fed. Cir., Sept. 7, 2010) (Lourie, J.)

Green Edge brought a patent infringement action against Rubber Mulch and Rubber Resources asserting infringement of a patent related to synthetic landscaping mulch. The district court granted summary judgment of invalidity based on a failure to disclose the best mode. The patent specification identified a preferred colorant for the synthetic mulch made by a particular supplier but with an incorrect product name. The specification identified the colorant by the name "Visichrome," a name the supplier did not use, while the actual colorant supplied was simply "product code 24009." The district court invalidated the patent, even though the correct supplier was identified and Green Edge had correspondence from the supplier identifying the product as "Visichrome."

The Federal Circuit began its analysis by reviewing the best mode requirement. Citing to its decision in Teleflex, the Court noted that the best mode requirement prevents an inventor from receiving the benefit of excluding others from practicing an invention, while simultaneously concealing the preferred embodiments of the invention from the public. A two-pronged inquiry is undertaken in a best mode analysis. First, did the inventor have a preferred mode, and second, if a preferred mode exists, did the inventor conceal it from the public? The first prong is subjective and focuses on the inventor’s preferences at the filing date. The second prong is objective and is based upon the scope of the invention and the level of skill in the art. The Federal Circuit noted that previous cases have held that the use of a proprietary product in a preferred embodiment requires the disclosure of supplier and trade name information to comply with the best mode requirement. The Court noted that, in this case, the specification contained the supplier name and a product name that the supplier had actually used with the inventor. Thus, if the supplier was contacted by a third party at the time of the patent filing, the supplier may well have known what product the third party was seeking, even though that product name did not exist. Thus, the Federal Circuit determined that a genuine issue of material fact existed as to whether the best mode was disclosed and summary judgment of invalidity was improperly granted by the district court.

Practice Note: When using proprietary products in the description of a preferred embodiment, it is imperative to properly identify the supplier of those products and the name the supplier uses for those products to ensure compliance with the best mode requirement.