YOU BE THE JUDGE 2
CASES
SHOW 05
Warner-Jenkinson Co., Inc. v. Hilton Davis Chemical Co., 520 U.S. 17 (1997).
Issue: Both parties manufacture dyes. Hilton has a patent on a purification process.
Warner developed a similar process and started using it commercially before learning
about Hilton’s process and patent. Hilton found out and sued. Hilton conceded no
literal infringement, but relied on the doctrine of equivalents.
Decision: The jury found a valid patent and infringement based on the doctrine of
equivalents. The jury also found that it was not intentional, and awarded only 20% of
the damages sought.
Significance: The critical test in any infringement suit, applying the doctrine of
equivalents, is whether the allegedly infringing device performs substantially the same
function in substantially the same way to obtain substantially the same result as the
patented product or process.
General Motors Corp. v. Devex Corp., 461 U.S. 648 (1983).
Issue: Devex Corp. sued GMC for infringement of a patent covering a lubricating
process used in the cold-forming of metal car parts by pressure.
Decision: Devex Corp. prevailed and the court determined what the annual royalty
payments would have been if GMC had sought to obtain a license from Devex, and
calculated prejudgment interest on each payment from the time it would have become
due, as well as awarding postjudgment interest.
Significance: In the typical patent infringement case, despite the common law
requirement of liquidation and exceptional circumstances, an award of prejudgment
interest is deemed necessary to ensure that the patent owner is placed in as good a
position as he would have been in had the infringer entered into a reasonable royalty
agreement.
Parker v. Flook, 437 U.S. 584 (1978).
Issue: Flook applied for a patent on a method for updating an alarm limit in the catalytic
conversion of hydrocarbons. Flook’s process used a mathematical algorithm to
accomplish this and contemplated the use of a computer.
Decision: The court held that the claim was nonpatentable, explaining that the patent, if
issued, would be on a law of nature. A law of nature, including its mathematical
manifestations, is not patentable.
Significance: While reiterating the longstanding rule that the law does not allow a patent
on an algorithm, the court conceded that a process is not nonpatentable simply because
an algorithm is involved. Rather, the court required that the claim demonstrate novelty
independent of the law of nature.
Pfaff v. Wells Electronics, Inc., 525 U.S. 55 (1998).
Issue: Pfaff invented a computer chip socket, had it manufactured, and began selling it.
Within a year of manufacturing it, he applied for a patent, and received one. Another
company started producing the same sockets, and Pfaff sued them for infringement.
Decision: Applying the rule that a patent is not valid if the product was on sale for more
than a year before the filing of the patent application, the court held that there was no
infringement because here, the commercial marketing of the new invention marked the
beginning of the one year period even though the invention had not yet been
manufactured.
Significance: If an invention is detailed enough to be commercially marketed and
manufactured, than the one year period within which one must file for patent protection
begins at that point, not when the invention has been successfully manufactured.