Avoiding the Patent Family Breakup With Careful Language
Summary: Patentee’s “incorporation by reference” language falls short of requirements, ends up invalidating its own patent
In Zenon Environmental, Inc., v. United States Filter Corp., No. 2006cv1266, 1267 (Fed. Cir. Nov. 7, 2007) (Newman, J., dissenting), the Federal Circuit reversed a district court’s judgment that Zenon’s U.S. Pat. 6,620,319 patent is not invalid as anticipated by U.S. Pat. No. 5,639,373, which is an ancestor of the ’319 patent. In doing so, the Federal Circuit found that the ‘319 patent does not adequately incorporate by reference the subject matter of its ancestor patents, thus breaking the chain of continuity that would otherwise remove the earlier family patents as prior art.
35 U.S.C. § 120, which governs entitlement to an earlier filing date in the United States, provides that:
An application for patent for an invention disclosed in the manner provided by the first paragraph of section 112 of this title in an application previously filed in the United States . . . which is filed by an inventor or inventors named in the previously filed application shall have the same effect, as to such invention, as though filed on the date of the prior application[.]
In order for the ’319 patent to be entitled to priority from the ’373 patent, the Federal Circuit said, continuity of disclosure must have been maintained throughout a chain of patents from the ’373 patent leading up to the ’319 patent. Incorporation by reference “provides a method for integrating material from various documents into a host document . . . by citing such material in a manner that makes clear that the material is effectively part of the host document as if it were explicitly contained therein.”
In this case, Zenon's incorporation by reference language stated that:
The vertical skein is not the subject matter of this invention and any prior art vertical skein may be used. Further details relating to the construction and deployment of a most preferred skein are found in the parent U.S. Pat. No. 5,639,373, and in Ser. No. 08/690,045, the relevant disclosures of each of which are included by reference thereto as if fully set forth herein.
The Federal Circuit found that the plain language above expressly limits the incorporation to only relevant disclosures of the patents, indicating that the disclosures are not being incorporated in their entirety. Moreover, the Court said that the plain language indicates that the subject matter that is being incorporated by reference pertains to the details relating to the construction and deployment of a vertical skein. Looking at the subject matter that was incorporated, the Federal Circuit found that “a reasonable person of ordinary skill in the art would understand that the gas distribution system covered by the ’373 patent is not a detail relating to the construction and deployment of a vertical skein, but rather is a separate and distinct element of the invention, and thus was not incorporated by reference in the ’250 patent [an earlier family patent].”
Accordingly, because the earlier ’250 patent failed to incorporate by reference, “with sufficient particularity to one reasonably skilled in the art, the gas distribution system disclosed in the ’373 patent, and thus a lack of continuity of disclosure exists in the family chain, the ’319 patent is not entitled to the filing date of the ’373 patent.” Because it was “undisputed that the ’373 patent discloses each and every limitation of the claims of the ’319 patent, and the ’373 patent was filed more than one year prior to the filing of the ’319 patent,” the Court conclude that the ’319 patent is anticipated by the ’373 patent and hence invalid.
