In US patent law, non-obviousness is one of the requirements that an invention must meet to qualify for patentability, codified as a part of Patent Act of 1952 as 35 U.S.C. §103. An invention is not obvious if a "person having ordinary skill in the art" (PHOSITA) would not know how to solve the problem at which the invention is directed by using exactly the same mechanism. Since the PHOSITA standard turned to be too ambiguous in practice, the U.S. Supreme Court provided later two more useful approaches which currently control the practical analysis of non-obviousness by patent examiners and courts: Graham et al. v. John Deere Co. of Kansas City et al., 383 U.S. 1 (1966) gives guidelines of what is "non-obvious", and KSR v. Teleflex (2006) gives guidelines of what is "obvious".
In the post-KSR (2006) patent legal practice in the US, the requirement for non-obviousness is often conflated with non-predictability. It is easier to find non-obviousness in non-predictable arts (such as pharmacology), and more difficult in predictable arts (such as business methods). Another contentious area is contradictions between non-obviousness and patentable subject matter requirements: whereas non-obviousness can be easily met, when inventor discovers something new and unexpected (like the discovery of the DNA segments corresponding to the fetus's father in the blood of pregnant women in Ariosa v. Sequenom),Why the Supreme Court Should Use Ariosa v. Sequenom to Provide Further Guidance on U.S.C. § 101 Patent Eligibility. 2016. The Chicago-Kent Journal of Intellectual Property. 16/1, 112. N.R. Simmons. a patent will be denied, as not meeting statutory subject matter requirement, "if the APPLICATION [of this discovery] merely relies upon elements already known in the art."USPTO Training materials on subject matter eligibility. 2023. https://www.uspto.gov/patents/laws/examination-policy/training-materials-subject-matter-eligibility; Why the Supreme Court Should Use Ariosa v. Sequenom to Provide Further Guidance on U.S.C. § 101 Patent Eligibility. 2016. The Chicago-Kent Journal of Intellectual Property. 16/1, 112. N.R. Simmons. (see also Mayo Collaborative Services v. Prometheus Laboratories, Inc. and Association for Molecular Pathology v. Myriad Genetics, Inc.) The alleged rationale for this dichotomy is to prevent broad patent claims that would inhibit rather than "promote the Progress of Science", as required by the Copyright Clause of the US Constitution.Fashena, S., Jackson, D. Patentability in the United States. Nat Rev Drug Discov 3, 381 (2004). https://doi.org/10.1038/nrd1388
Historical development Constitutionally, the non-obviousness requirement is established by Article 1, Section 8, Clause 8: "The Congress shall have the power ... to promote the Progress of Science .., by securing for limited Times to ... Inventors the exclusive Right to their ... Discoveries". The phrase to promote the Progress of Science defines the purpose of the patent system, which is to encourage private investments into fundamental science research rather than to grant monopoly on something that is taken from a public domain (or on something that limits the opportunities for doing research, e.g. research tools are not patentable). The Progress of Science requirement constitutionally validates the pragmatic approach to non-obviousness described below. The word Discoveries establishes the level to which the contribution to the Progress of Science must rise to deserve the temporary monopoly.CHENETTE, S. (2008). "Maintaining the Constitutionality of the Patent System." Hastings Constitutional Law Quarterly 35(2): 221-262. www.hastingsconlawquarterly.org/archives/V35/I2/Chenette.pdf
1790-1850: the early days The first patent statute enacted by the Congress in 1790 required patentable inventions or discoveries to be "sufficiently useful and important". One can interpret important as important for the Progress of Science since the importance for economy is stated by useful. The next Patent Act of 1793 did not have the important language, but stated that "simply changing the form or the proportions of any machine, or compositions of matter, in any degree, shall not be deemed a discovery." (This statement was actually adopted from the French Patent Law of 1791). This was echoed in Thomas Jefferson's 1814 letter explaining that changing material, for example, from cast iron to wrought iron was insufficient for patentability.See Graham v. John Deere Co., 383 U.S. 1, 10 n.3 (1966) ("[A] change of material should not give title to a patent. As the making a ploughshare of cast, rather than of wrought, iron; a comb of iron, instead of horn or of ivory. . . ."
The difficulty of formulating conditions for patentability was heightened by the generality of the constitutional grant and the statutes implementing it, together with the underlying policy of the patent system that "the things which are worth to the public the embarrassment of an exclusive patent", as Jefferson put it, must outweigh the restrictive effect of the limited patent monopoly. The 1836 Patent Act did not have the "simply changing" language but stated instead that the Commissioner of Patents was authorized to issue a patent for any "sufficiently used and important" invention or discovery.
The U.S. Supreme Court considered the issue of inventiveness/non-obviousness/discovery for the first time in 1822 in Evans v. Eaton (20 US 356,431) when it approved the interpretation of a lower court that a patentable improvement must involve a change in the "principle of the machine" not "a mere change in the form or proportions". Currently, such variations are usually interpreted as a lack of novelty not of an inventive step.
1851–1951: struggles to find practical criteria The issue of non-obviousness reached the U.S. Supreme Court again in 1851 in Hotchkiss v. Greenwood. The question was whether a substitution of known door knob materials such as metal or wood for a new material—porcelain—deserved a patent. The court concluded that "the improvement is the work of a skillful mechanic, not that of the inventor" and invalidated the patent. Such approach foresees the line of thought which was later formulated as the PHOSITA (person having ordinary skill in the art) approach to the analysis of inventiveness. Despite beginning to develop the PHOSITA approach, the Court did not give practical means to determine what how much inventiveness deserves a patent. It is worth noting here that Evans v. Eaton and Hotchkiss v. Greenwood, respectively, illustrate the heretofore existing trend to state the appropriate inventiveness by defining both what is obvious (lacks an inventive step / discovery) and what is non-obvious (has an inventive step / discovery).
During the period from 1851 to 1951, several new cases related to the non-obviousness of claimed subject matter in patents reached the Supreme Court. One noteworthy case is Rubber-Tip Pencil Co. v. Howard 87 U.S. (20 Wall.) 498 (1874), in which the Supreme Court invalidated a patent on a pencil with a rubber eraser cap, on the theory that everyone knows rubber will stick to wood inserted into a hole in the rubber. In another noteworthy case, Sinclair & Carrol Co. v. Interchemical Corp. (1945), the U.S. Supreme Court found that a patent was "not the product of long and difficult experimentation", and that "reading a list and selecting a known compound to meet known requirements is not more ingenious than selecting the last piece to put into the last opening in a jig-saw puzzle".
However, during that time the Courts struggled to find both the required levels of inventiveness and obviousness and practically useful criteria to measure these levels. One notable example of this struggle is the 1941 US Supreme Court case of Cuno Engineering v. Automatic Devices Corp., which was said to establish the flash of genius doctrine as a test of patentability of an invention: "the new device must reveal the flash of creative genius, not merely the skill of the calling".
The Flash of Genius approach was thought to have shifted the analysis of inventiveness from importance and from PHOSITA to the state of mind of the inventor; it caused uproar in the patent law community as courts struggled to find alternative approaches. One notable example of this struggle is the positions of Justice Douglas in Great Atlantic & Pacific Tea Co. v. Supermarket Equipment Corp. in 1950, where he opined that to deserve a patent, an invention "had to serve the end of science—to push back the frontiers of chemistry, physics, and the like"; while two years prior in Funk Bros. Seed Co. v. Kalo Inoculant Co. he stated that the discovery of a new natural principle—is not patentable of itself, "however ingenious the discovery of this natural principle may have been".
Similar problem arose again in Mayo Collaborative Servs. v. Prometheus Labs., Inc. (2012), where the U.S. Supreme Court majority stated: "The conclusion is that (1) a newly discovered law of nature is itself unpatentable and (2) the application of that newly discovered law is also normally unpatentable if the application merely relies upon elements already known in the art." It is worth noting, however, that this opinion remains highly controversial; as Justice Stephen Breyer stated, it risked rendering "all inventions unpatentable because all inventions can be reduced to underlying principles of nature which, once known, make their implementation obvious."
This position raised issues as to a need to establish the boundary of the patentable domain, not only with routine improvements but also with major advancements in science, i.e. creating too much monopoly which may impede rather that promote the Progress of Science. Currently, the latter boundary is established via the requirement for patent-eligible subject matter (research tools, scientific theories and laws are not patent eligible) while the issue of how much inventiveness is required to deserve a patent is supposed to be defined via the non-obviousness requirement.
The trend that started to develop around 1950 (and dominates today) was to require disclosure of an element of discovery, while granting patent monopoly on only one or a few "particular applications of [natural] laws" that the discoverer came up with before the very first disclosure becomes published. The duality between the non-obviousness requirement and an overbroad scope of claims is expected to receive further development by the U.S. Supreme Court in due course.
The U.S. Supreme Court's decision in Great Atlantic & Pacific Tea Co. v. Supermarket Equipment Corp. in 1950 is often considered the high-water mark of the pragmatic approach, as the Court reversed (after affirmations in two lower courts) the patent grant of a commercially successful but very simple mechanical device as merely a "gadget". Based on its decision that a combination "which only unites old elements with no change in their respective functions" is unpatentable because such a patent would "obviously withdraw what already in known into the field of its monopoly and diminish . . . the resources available to skillful men."340 U.S. at 152-53; Duffy p. 671. Another example of insufficient inventiveness of that time can be found in In re Aller (CCPA, 1955) "It is not inventive to discover the optimum or workable ranges by routine experimentation." This restriction was, however, lifted later in cases where "a parameter must be recognized as a result-effective variable before a determination of routine experimentation".In re Antonie - Federal Circuit, 1977.