Nonobviousness

What nonobviousness requires

Nonobviousness under 35 U.S.C. § 103 is a patentability requirement that separates genuine inventions from minor variations of existing technology. An invention is obvious — and thus unpatentable — if the differences between it and the prior art would have been obvious at the time of the effective filing date to a person of ordinary skill in the art (POSITA). Obviousness does not require that a single prior art reference discloses every element of the invention (that would be anticipation under § 102) — it requires that a POSITA looking at the prior art collectively would have been motivated to make the claimed combination or modification. Most patent rejections in US prosecution are § 103 obviousness rejections, not § 102 novelty rejections, because examiners can combine multiple references.

The Graham v. John Deere four-factor test

Graham v. John Deere Co. (S.Ct. 1966) established the constitutional and statutory framework for obviousness. The four factors are: (1) the scope and content of the prior art — what does each relevant reference actually teach? (2) the differences between the prior art and the claimed invention — what is the delta that the claimed invention adds? (3) the level of ordinary skill in the pertinent art — what is the POSITA's background knowledge and what would they be able to accomplish? (4) secondary considerations (objective indicia of nonobviousness) — commercial success, long-felt need, failure of others, unexpected results. All four factors must be considered together. The Graham factors are factual inquiries; the ultimate determination of obviousness is a legal conclusion. In district court, the factual findings must be proven by clear and convincing evidence to overcome the presumption of validity (§ 282); at the USPTO and PTAB, the standard is preponderance of the evidence.

KSR and the flexible standard

KSR International Co. v. Teleflex Inc. (S.Ct. 2007) significantly changed how obviousness is analyzed by rejecting the rigid 'teaching-suggestion-motivation' (TSM) test. Pre-KSR, the Federal Circuit required an explicit teaching, suggestion, or motivation in the prior art itself to combine references — if no reference expressly suggested the combination, it was not obvious. Post-KSR, the Court held that a POSITA has 'ordinary creativity' and can: combine familiar elements using known methods to yield predictable results; use simple substitution of known elements with predictable results; apply a known technique to a known problem with obvious design choices; and pursue obvious-to-try approaches where there are 'a finite number of identified, predictable solutions.' KSR also held that the motivation to combine can come from common sense, the nature of the problem being solved, or design needs — not just from explicit prior art teachings.

Motivation to combine

The core analytical question in most obviousness rejections is whether a POSITA would have been motivated to combine or modify the relevant prior art references and would have had a reasonable expectation of success. The motivation analysis asks: why would a skilled artisan have thought to combine these references in this particular way? Acceptable motivations include: solving a recognized problem in the field; improving efficiency, cost, or performance in a known direction; combining complementary technologies routinely used together; following a recognized trend or direction in the prior art; and design choices that are within the ordinary skill level. After KSR, 'obvious to try' is a valid rationale when there are a finite number of known, predictable solutions to a recognized problem — if the claimed invention selects one from a small set of recognized alternatives, that selection may be obvious. The applicant can rebut by showing the combination would have been expected to fail, produce unpredictable results, or require more than ordinary skill.

Secondary considerations as rebuttal

Secondary considerations (objective indicia of nonobviousness) are part of the mandatory Graham analysis and can rebut a prima facie case of obviousness. The main secondary considerations are commercial success (attributable to the claimed features — nexus required), long-felt but unsolved need, failure of others, and unexpected results. KSR reaffirmed that secondary considerations 'must always be considered' even when the prior art appears to teach directly to the invention. Courts have found secondary considerations sufficient to overcome a strong prior art case — particularly when the combination of long-felt need, failure of others, and unexpected results is well-documented. In USPTO prosecution, secondary consideration evidence is presented through 37 C.F.R. § 1.132 declarations by the inventor, technical experts, or marketing/business experts. Evidence should be specific, tied to claimed features (nexus), and ideally contemporaneous with the invention rather than assembled post-litigation.

Obviousness in IPR proceedings

Inter Partes Review (IPR) is the most common tool for challenging patent validity at the Patent Trial and Appeal Board (PTAB). IPR challenges are limited to §§ 102 and 103 — novelty and obviousness — based on prior art patents and printed publications. The evidentiary standard at PTAB is preponderance of the evidence (lower than the clear and convincing evidence standard required in district court to overcome the presumption of validity). PTAB institution rates for obviousness challenges are historically around 60-65%; challenged claims are cancelled at roughly 70-75% of cases that are instituted. For patent owners, strong obviousness challenges are best addressed by: (1) identifying weaknesses in the motivation to combine argument; (2) challenging whether the references actually teach all claimed elements; (3) submitting secondary considerations evidence; and (4) presenting expert testimony from a credible POSITA on whether the combination would have been expected to work.

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