106 Iowa L. Rev. 1609 (2021)
Download PDF


The requirement of nonobviousness, codified in 35 U.S.C. § 103, has been called “the ultimate condition of patentability” because of its crucial function of keeping technically trivial inventions out of the patent system. The obviousness determination must be made based on the state of the invention’s field at a particular point in time—in the Patent Act’s current version, the date that the patent application was effectively filed with the U.S. Patent and Trademark Office (“PTO”).

However, in spite of the critical role of time in patent law and the danger that hindsight bias could distort § 103 analysis when patentability is evaluated long after the relevant date (as it usually is), the seminal Supreme Court obviousness opinion in Graham v. John Deere said little about temporal considerations. Instead, Graham’s lasting contribution was to suggest that the § 103 inquiry is to be divided into two stages based on the source of the proffered evidence. The Court said that as an initial matter, the PTO or a court should look to pre-patent publications and other materials in the public domain and determine the differences between those disclosures and the patent claim at issue. Further, should the parties introduce additional evidence that the Court called “secondary considerations,” such as commercial success of the patented product or failure of others to come up with the claimed invention, decision-makers would need to continue the analysis to determine the relevance and weight of this evidence before making a final judgment on validity. Although courts and commentators disagree vigorously about the relative roles of these two aspects of the nonobviousness calculus, the primary-secondary framework has a central place in the law of § 103.

This Article shows that Graham’s apparent creation of two tiers of obviousness evidence has caused confusion and error, and should be rejected in favor of a different approach that is focused on time. First, the rigid segmenting of the patentability inquiry into two steps, which is seen in some lower-court decisions interpreting Graham, has caused certain evidence to be arbitrarily discounted or bolstered depending on whether it falls into the primary or secondary silo. Second, and more pernicious, these evidentiary tiers have obscured the significance of time for patentability. This Article argues that, instead, the filing date of the patent application as the default dividing line between the pre- and post-invention state of the relevant field provides a more logical fulcrum around which to organize the § 103 analysis. Accordingly, obviousness evidence should be classified based on whether it came into existence independently of the patent and generally prior to filing (ex ante) or, instead, whether it appeared in response to the invention or during its further, post-filing, development (ex post). This Article demonstrates that the proposed scheme would pave the way to a more rational approach to § 103 by helping decision-makers determine the relevance and weight of various obviousness evidence with greater accuracy.

Tuesday, June 15, 2021