E. I. du Pont de Nemours & Co. v. Berkley & Co. Inc.

620 F.2d 1247, 205 U.S.P.Q. 1 (1980)

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E. I. du Pont de Nemours & Co. v. Berkley & Co. Inc.

United States Court of Appeals for the Federal Circuit
620 F.2d 1247, 205 U.S.P.Q. 1 (1980)

Facts

E. I. du Pont de Nemours & Company (DuPont) (plaintiff) held a patent on a fluorescent-dyed fishing line. Berkley & Company, Inc. (Berkley) (defendant) sold a product that copied the patented invention and, in the process, made more than $7.5 million. DuPont sued Berkley for infringement in federal district court. Berkley admitted to copying elements of the invention but alleged that the patent was invalid for lack of utility. This argument was based on tests showing that the dyed fishing line did not glow under certain conditions. The issue of invalidity due to lack of utility was among the issues presented to the jury. The jury returned a verdict for Berkley, which was entered by the court. DuPont appealed to the United States Court of Appeals for the Federal Circuit.

Rule of Law

Issue

Holding and Reasoning (Markey, C.J.)

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