By Jason Rantanen
DePaul Professor Joshua Sarnoff has a new article addressing a recently reinvigorated subject: the doctrine of equivalents. In Correcting Misunderstandings of Literal Infringement Scope Regarding After-Arising Technologies Protected By the Doctrine of Equivalents, forthcoming in the Akron Law Review, Professor Sarnoff argues that while it is conventional wisdom that, for purposes of ‘literal’ infringement, interpreted claim meaning and the application of such meaning can expand over time to encompass after-arising, equivalent technologies, this conventional wisdom is wrong: “current case law regarding literal infringement does not authorize claims to literally encompass or apply to after-arising technologies.” Id. at 6.
The term “after-arising technologies” refers to the idea that there are technologies that are developed after an application is filed or a claim is written. Due to the centrality of time to patent law, a central question in patent law is whether a patent’s claims can (and should) encompass technologies that were unknown–and indeed may have been unforseeable–at the time the claim was drafted. Excellent examples of this problem can be found in Kevin E. Collins, The Reach of Literal Claim Scope into After-Arising Technology: On Thing Construction and the Meaning of Meaning, 41 Conn. L. Rev. 493 (2008) and Robert P. Merges & John F. Duffy, Patent Law and Policy: Cases and Materials, 7th ed. (2017), at 273-277 (discussing the “temporal paradox” mostly in the context of enablement).
Professor Sarnoff advances his premise through several arguments, drawing from the Federal Circuit’s precedent in Schering Corp. v. Amgen, which “limits the temporal meaning and scope of application for literal infringement to equivalent technologies known to be embodiments of the claim language as of effective filing date of the claim,” as well the statutory interpretive rule of § 112(f). Sarnoff at 3.
Central to Professor Sarnoff’s premise is the corollary that:
If claim meaning or the scope of application of such meaning can expand over time for literal infringement purposes, then there is less need to resort to the doctrine of equivalents to protect against after-arising technologies. However, if claim meaning or application scope is limited to technologies that were known as of the filing date to be claim embodiments, then the doctrine of equivalents is necessary for any such protection.
Id. at 1. Thus, Professor Sarnoff argues, decreased ability to rely on literal claim scope to reach after-arising technologies puts more pressure on the doctrine of equivalents–indeed, it’s ability to encompass after-arising technologies has been offered as a primary justification for the doctrine. But this additional pressure creates its own problems given the fuzziness of scope that the doctrine of equivalents allows. Restricting literal claim scope to known embodiments may also conflict with the ‘”pioneering invention patent doctrine,” to the except that doctrine continues to be viable.
Read the whole article here: http://ssrn.com/abstract=3549932