Obviousness & Motivation to Combine
Building motivation-to-combine arguments under KSR v. Teleflex and the analogous-art test of In re Clay when the prior art comes from unrelated fields — with Wyers v. Master Lock as the challenger's lead authority.
Motivation to Combine Across Unrelated Fields After KSR
The obviousness analysis "cannot be confined by a formalistic conception of the words teaching, suggestion, and motivation." KSR International Co. v. Teleflex Inc., 550 U.S. 398 (2007). Combining familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results, and any need or problem known in the field and addressed by the patent can supply the reason to combine. KSR speaks directly to cross-field disputes: when a work is available in one field of endeavor, design incentives and market forces can prompt variations of it "either in the same field or a different one."
When the references come from unrelated fields, the threshold fight is analogous art. A reference qualifies only if it comes from the same field of endeavor as the invention, regardless of the problem it addresses, or — if outside that field — is reasonably pertinent to the particular problem confronting the inventor, meaning it "logically would have commended itself to an inventor's attention in considering his problem." In re Clay, 966 F.2d 656 (Fed. Cir. 1992). A shared purpose supports pertinence; a different purpose gives the inventor less occasion to consider the reference.
The challenger leads with breadth. Wyers v. Master Lock Co., 616 F.3d 1231 (Fed. Cir. 2010) reads KSR as directing courts to construe the scope of analogous art broadly because "familiar items may have obvious uses beyond their primary purposes," and it permits the motivation to combine to rest on logic, judgment, and common sense in lieu of expert testimony. Donner Technology, LLC v. Pro Stage Gear, LLC, 979 F.3d 1353 (Fed. Cir. 2020) vacated a Board decision that defined the inventor's problem so narrowly it excluded all outside art: reasonable pertinence must be assessed from the perspective of a skilled artisan who is already considering references beyond her field, and significant differences between the reference and the patent do not, standing alone, defeat pertinence.
The patentee's answer is that the analogous-art requirement survived KSR intact. A reference qualifies as prior art under § 103 "only when it is analogous to the claimed invention," and on that ground In re Klein, 647 F.3d 1343 (Fed. Cir. 2011) reversed an obviousness rejection: the cited references were not reasonably pertinent to the inventor's particular problem. Circuit Check Inc. v. QXQ Inc., 795 F.3d 1331 (Fed. Cir. 2015) supplies the strongest limiting principle: a challenger cannot "transform all systems and methods within the common knowledge into analogous prior art" simply by asserting that anyone would have known of them — the question is whether an inventor would look to this particular art to solve the particular problem at hand. In re Clay itself models the analysis, finding a reference on plugging underground formations not reasonably pertinent to the problem of dead volume in tanks storing refined petroleum.
Whether a reference is analogous is a question of fact, so the patentee should build a record that stresses the reference's different purpose and operating context. The challenger should define the problem at the level of generality a skilled artisan would recognize — and, where the technology is easily understandable, press the issue early. Wyers confirms that expert testimony on motivation to combine is not always required and that obviousness may be resolved on summary judgment in appropriate circumstances.