Warner-Jenkinson Company Inc v. Hilton Davis Chemical Co’s Empirical Analysis
1997
Citation profile
519 federal appellate · 780 district · 10 state decisions
How this case has been cited
Cited by 3,206 later decisions (16 by the Supreme Court) — most recently January 2025 · most notably Cybor Corporation v. Fas Technologies, Inc., and Fastar Ltd., Defendants-Cross (1998), Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co. (2002)
519 federal appellate · 780 district · 10 state decisions
Later decisions citing this case, by decade. The current decade is in progress, and our corpus holds fewer opinions from the most recent years, so the latest bars are undercounted — not a real decline.
Appellate journey
reviewedthe decision below (from Federal Circuit Court of Appeals)
Relationships
Applies 35 U.S.C. § 100 · 35 U.S.C. § 112
Relies on Celotex Corporation v. Catrett H · Graham v. John Deere Company of Kansas City Calmar Inc · MARKMAN Et Al. v. WESTVIEW INSTRUMENTS, INC., Et Al. · Graver Tank & Mfg. Co. v. Linde Air Products Co.
Cited together with MARKMAN Et Al. v. WESTVIEW INSTRUMENTS, INC., Et Al. · Anderson v. Liberty Lobby, Inc. · Graver Tank & Mfg. Co. v. Linde Air Products Co. · Celotex Corporation v. Catrett H · Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co.
Most-quoted passages
The sentences later courts lift from this opinion, ranked by how many decisions quote each — the parts of the opinion doing the work. These counts are smaller than the citation total above because most of the 3,206 citing decisions cite the case generally; a passage count includes only decisions quoting that exact language verbatim.
“Each element contained in a patent claim is deemed material to defining the scope of the patented invention, and thus the doctrine of equivalents must be applied to individual elements of the claim, not to the invention as a whole. It is important to ensure that the application of the doctrine, even as to an individual element, is not allowed such broad play as to effectively eliminate that element in its entirety.”
50 later decisions quote this exact passage · from the dissent“[w]here the evidence is such that no reasonable jury could determine two elements to be equivalent, district courts are obliged to grant partial or complete summary judgment.”
34 later decisions quote this exact passage · from the dissent“An analysis of the role played by each element in the context of the specific patent claim will thus inform the inquiry as to whether a substitute element matches the function, way, and result of the claimed element, or whether the substitute element plays a role substantially different from the claimed element.”
24 later decisions quote this exact passage · from the dissent
How this case has been treated — in progress
Whether each later court followed, distinguished, criticized, or overruled this decision. The treatment classification (task #35) runs highest-cited cases first and lights up here as it reaches this one.