Early Filing and Functional Claiming

A major problem in the patent system is that many patents claim far more than the patentee actually invented. In his perceptive article, Ready for Patenting, Mark Lemley argues that this overclaiming is caused in part by legal doctrines that encourage inventors to file a patent application as early as possible, often before — or even instead of — building their invention. Patents issued from early-filed applications, Lemley argues, tend to be overly broad because the applicant does not yet know how the invention actually works. This response essay, part of the Boston University Law Review’s symposium on Notice Failure in Intellectual Property Law, engages Lemley’s article in two ways. First, although it agrees that patent law should, in general, offer more protection to patentees who build their inventions than it offers to mere “paper patentees,” it emphasizes that protecting builders can be costly. Doctrines that encourage inventors to build their inventions before they file a patent application, such as the experimental use doctrine, are fact-intensive to apply and can encourage expensive litigation. By contrast, doctrines that reduce the importance of building the invention, such as the new first-to-file priority rule, are easy and cheap to apply. Although the social costs of overbroad patents that result from early filing might outweigh the expense of occasional, complicated fights over novelty and priority, Lemley’s argument against early filing would be stronger if it engaged the tradeoff between clear rules and fuzzy standards in this area. Second, the essay builds on Lemley’s argument that functional claiming is a key source of overly broad patent protection by analyzing the effects of the Federal Circuit’s 2015 en banc decision in Williamson v. Citrix Online, LLC, which gave courts new discretion to constrain the scope of patents drafted in functional terms. Recent district court decisions make clear that Williamson provides a ground to narrow or even to invalidate particularly broad, functional patent claims. But the decisions also provide a roadmap for future patent applicants to draft around Williamson’s limits on claim scope. Accordingly, other doctrines, such as the requirement of patent eligibility under § 101 of the Patent Act, will continue to be important to combating overclaiming in patent law