Judging Equivalents

59 Pages Posted: 20 Aug 2019 Last revised: 11 May 2020

See all articles by Daryl Lim

Daryl Lim

Pennsylvania State University, Dickinson Law; Fordham University - Fordham Intellectual Property Institute

Date Written: August 16, 2019


Courts, patent attorneys, and legal scholars have wrestled with operationalizing the doctrine of equivalents for nearly 150 years. A venerable exception to normal patent infringement rules, the doctrine is deceptively simple to state—it enables patentees to reach beyond the literal wording of their claims, but it remains extremely controversial in its application. This Article traces the doctrine’s origins and explains the reasons for the doctrine’s incoherence, the tension between judges and juries, and the decline of the doctrine. This Article complements the doctrinal discussion with empirical findings of interest to academics and practitioners, including “equitable triggers” such as copying, design-arounds, and pioneer inventions. It also investigates limits such as prosecution history estoppel, the “all-elements” rule, the prior art bar and the public dedication rule.

Keywords: Patent, doctrine of equivalents, empirical

Suggested Citation

Lim, Daryl, Judging Equivalents (August 16, 2019). Santa Clara Computer and High Technology Law Journal, Vol. 36, 2020, Available at SSRN: https://ssrn.com/abstract=3438432 or http://dx.doi.org/10.2139/ssrn.3438432

Daryl Lim (Contact Author)

Pennsylvania State University, Dickinson Law ( email )

150 S College St
Carlisle, PA 17013
United States

HOME PAGE: http://lawdaryl.com

Fordham University - Fordham Intellectual Property Institute ( email )

150 West 62nd Street, Rm 7-145
New York, NY 10023
United States

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