Pfaff v. Wells Electronics, Inc.’s Empirical Analysis
1998
Citation profile
176 federal appellate · 150 district · 4 state decisions
How this case has been cited
Cited by 782 later decisions (19 by the Supreme Court) — most recently April 2025 · most notably Eldred v. Ashcroft (2003), Microsoft Corp. v. i4i Ltd. Partnership (2011)
176 federal appellate · 150 district · 4 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. § 102 · 35 U.S.C. § 103
Relies on Bonito Boats, Inc. v. Thunder Craft Boats, Inc. · Johnson v. Railway Express Agency, Inc. · Seymour v. Osborne · Elizabeth v. Pavement 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 782 citing decisions cite the case generally; a passage count includes only decisions quoting that exact language verbatim.
“by proof of reduction to practice before the critical date; or by proof that prior to the critical date the inventor had prepared drawings or other descriptions of the invention that were sufficiently specific to enable a person skilled in the art to practice the invention.”
45 later decisions quote this exact passage · from the majority“the invention was . . . on sale in this country, more than one year prior to the date of the application for patent in the United States.”
21 later decisions quote this exact passage · from the majority“that an invention [can be] ... complete and ready for patenting before it has actually been reduced to practice.”
14 later decisions quote this exact passage · from the majority
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.