Faculty Journal Articles and Book Chapters


The Federal Circuit’s standard for proving invalidity of patent claims is clear. The Federal Circuit always requires clear and convincing evidence to prove that a patent claim is invalid. The rationale behind this standard, however, is unconvincing. There are significant reasons to believe that the Patent Office rarely considers the most relevant prior art and that, instead, alleged infringers often find prior art that is more relevant than the prior art considered by the Patent Office. It defies logic to apply the clear and convincing burden where the Patent Office considered only prior art that is less relevant than the prior art asserted in litigation. And while the Federal Circuit relies upon 35 U.S.C. § 282 as dictating the clear and convincing burden of proof, the statute includes no such burden. Indeed, every other circuit court of appeals has indicated that the statutory presumption of validity only requires a presumption that the Patent Office correctly ruled upon the evidence in front of it - not that the Patent Office considered the most relevant prior art or that it - illogically - correctly ruled upon evidence that it did not even consider. To encourage the disclosure of relevant prior art to the Patent Office, to increase patent quality, to ensure that patents serve their Constitutional purpose of rewarding inventors for disclosing discoveries, and to reduce transaction costs associated with ultimately invalid patents, the clear and convincing burden of proving invalidity should be replaced with a preponderance burden when litigation involves unconsidered, material prior art.

Publication Title

Fordham Intellectual Property, Media & Entertainment Law Journal

Document Type




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