Federal Circuit Clarifies Rule on Completeness of Patents in a Sequence

By Sarah Sorscher — Edited by Johnathan Jenkins

Zenon Environmental, Inc. v. United States Filter Corp.
Federal Circuit, November 7, 2007, No. 2006-1266
Slip Opinion

On November 7, the Federal Circuit reversed the District Court of the Southern District of California, which had found Zenon’s patent for a water filtration device not invalid by reason of anticipation in a bench trial.

The Federal Circuit held that, because an intervening patent failed to contain an essential element of the patent at issue, the patent at issue was indeed invalid by reason of anticipation. At issue was the correct application of 35 U.S.C. § 120, which entitles an inventor to maintain the benefit of the filing date of the earliest patent in a sequence, provided subsequent patents remain linked to that first patent by an unbroken chain of disclosures.

Dennis Crouch of Patently-O provides further details on the holding.
PLI’s Gene Quinn takes issue with the court’s decision to resolve the case as a matter of law.

Zenon’s invention, described in the patent under consideration (the ’319 patent), involved at least two separate and distinct elements: a “vertical skein” and a “gas distribution system.” Both elements were present in the first patent in the sequence (the ’373 patent). Judge Lourie’s majority opinion considered whether language in the intervening ’250 patent “incorporated by reference, with sufficient particularity to one reasonably skilled in the art, the gas distribution system disclosed in the ’373 patent.” Treating that question as a matter of law subject to de novo review, the court held that the ’250 patent failed to incorporate by reference the gas distribution system disclosed in the ’373 patent, thus breaking the “family chain.” Because the ’319 patent contains each and every claimed inventive element in the ’373 patent, the court held that a break in the chain made the ’319 “grandchild” invalid by reason of anticipation by its own “grandparent,” the ’373 patent.

In dissent, Judge Newman argued that the majority was wrong to disregard the district court’s findings on what would be “reasonably conveyed to a person skilled in the relevant art,” and that it had misapplied the rules of incorporation by reference and “converted fact into law.” Judge Newman characterized the ruling as adding a new requirement that “all subject matter must be reproduced in all continuing applications,” and declared that this task “adds nothing the knowledge disclosed to the public, adds nothing to the information provided to the patent examiner, and adds nothing to compliance with 35 U.S.C. §120; it simply adds costs and pitfalls to inventors, as they attempt to walk new judicial tightropes.”