Warner-Jenkinson Company, Inc. v. Hilton Davis Chemical Co.

SCOTUSCase
Litigants=Warner-Jenkinson Company, Inc. v. Hilton Davis Chemical Co.
ArgueDate=October 15
ArgueYear=1996
DecideDate=March 3
DecideYear=1997
FullName=Warner-Jenkinson Company, Incorporated, et al. v. Hilton Davis Chemical Company
USVol=520
USPage=17
Citation=117 S. Ct. 1040; 137 L. Ed. 2d 146; 1997 U.S. LEXIS 1476; 65 U.S.L.W. 4162; 41 U.S.P.Q.2D (BNA) 1865; 97 Cal. Daily Op. Service 1540; 97 Daily Journal DAR 2249; 10 Fla. L. Weekly Fed. S 321
Prior=On writ of certiorari to the United States Court of Appeals for the Federal Circuit
Subsequent=
Holding=
SCOTUS=1994-2005
Majority=Thomas
JoinMajority="unanimous"
Concurrence=Ginsburg
JoinConcurrence=Kennedy
LawsApplied=

"Warner-Jenkinson Company, Inc. v. Hilton Davis Chemical Co.", 520 U.S. 17 (1997)ref|citation, was a United States Supreme Court decision in the area of patent law, affirming the continued vitality of the doctrine of equivalents while making some important refinements to the doctrine.

Facts

The plaintiff, a dyemaker, had developed an "ultrafiltration" process to purify dyes. An amendment to the patent had specified that a solution used in the process must have a pH level between 6.0 and 9.0. The amendment was filed in order to clarify that this patent did not overlap with a previously patented process that used a solution with a pH level above 9.0 - however, the plaintiff was unable to explain why the amendment stated a "lower" level of 6.0. The defendant had developed a process using a solution with a pH level of 5.0, which was outside the range of the plaintiff's patent.

The plaintiff sued for infringement, conceding that the defendant's process did not "literally" infringe, but relying on the doctrine of equivalents to support the claim of infringement. The defendant argued that the doctrine of equivalents was no longer appropriate for courts to use because Congress had made some changes to the patent statute after the Supreme Court's 1950 decision establishing the propriety of using the doctrine.

Issue

Is the doctrine of equivalents still in force? How is the plaintiff's amendment to figure into the problem?

Result

The Court, in an opinion by Justice Clarence Thomas, held that the doctrine of equivalents had not been eliminated by changes to the patent statute. Instead, the Court determined that Congress would have explicitly stated that they were eliminating the doctrine if that was their intent.The Court enunciated a test for amendments, finding that if the plaintiff can prove the reason for the amendment was not to limit the patent, then infringement was still possible.The case was remanded to the trial court to determine if the plaintiff could explain his lower pH limit.

Concurrence

Justice Ruth Bader Ginsburg wrote a concurring opinion, in which Justice Anthony Kennedy joined, expressing some concern about whether patentees would have sufficient notice that they must explain the reasons for their amendments. Nevertheless, they agreed with the remand to the lower court to establish the plaintiff's reason for setting a lower limit.

External links

*ussc|520|17|Text of the opinion on Findlaw.com