Is It Hindsight Or Was It Already There?

Background

Inherency and obviousness are two well-known and well-recognized U.S. patent law doctrines with fundamental differences. Inherency is a fact issue, requiring a showing that the feature or limitation at issue is either necessarily present in, or the natural result of, the elements explicitly disclosed by the prior art. Obviousness, on the other hand, is a matter of law based on findings of underlying facts. The obviousness analysis examines the knowledge of a person of ordinary skill in the art at the relevant time.  

Because inherency focuses on what was disclosed in the prior art, analyzing whether a claim limitation is inherent can involve looking back, for example by examining prior art features, to determine if a claim limitation was inherently disclosed. In contrast, the obviousness analysis forbids hindsight, focusing only on what a person of ordinary skill in the art would have recognized on the relevant critical date.¹