To defeat obviousness, patent owners have long relied on the ability to show a reference is not analogous art. Although a long standing legal principle, this issue was recently addressed in The Nielsen Company (US), LLC v. TVision Insights, Inc., Case No. 2025-1371 (Fed. Cir. 2026)[1] where the Federal Circuit affirmed the Patent Trial and Appeal Board’s (PTAB) determination that a facial analysis reference qualified as analogous art to claims directed to audience measurement technology.
The Nielsen decision provides two lessons. First, a challenger need not identify each analogous art theory expressly. A reasonable pertinence theory may be implicit when the challenger provides adequate notice through its discussion of the claims, prior art, and reasons to combine. Second, the problem is not limited to the problem emphasized in the specification. The Office or court may consider broader problems reflected in the claims.
The Analogous Art Framework
A reference qualifies as analogous art if it satisfies either of two independent prongs:
- The reference is from the same field of endeavor as the claimed invention; or
- The reference is reasonably pertinent to a problem facing the inventor.
The Federal Circuit’s Application of the Framework
Federal Circuit precedent illustrates the breadth and limits of the analogous art inquiry. In In re Klein, 647 F.3d 1343 (Fed. Cir. 2011), references involving divided storage containers were outside the invention’s field and did not address the problem of preparing different nectar concentrations. Klein remains an example of art too remote from the invention’s field and problem. Another seminal case was Netflix, Inc. v. DivX, LLC, 80 F.4th 1352 (Fed. Cir. 2023) in which the Federal Circuit vacated and remanded the Board’s finding that Netflix had not established the Kaku reference as analogous art, despite Netflix’s argument that Kaku and the challenged patent both involved Audio Video Interleave file formats and multimedia encoding. Specifically, the Federal Circuit vacated and remanded the Board’s field of endeavor determination, explaining that a petitioner need not use “magic words” to define the field. Instead, the Board must consider the substance of the petitioner’s arguments and evidence.
The Dispute in Nielsen at the PTAB and Federal Circuit
Nielsen arose from an IPR of U.S. Patent No. 11,470,243, titled “Methods and Apparatus to Capture Images.” The patent concerns audience measurement systems that capture and analyze images of media audiences.
The challenged claims required reducing an image’s resolution and determining head orientation from the reduced resolution image. Certain dependent claims required generating a facial signature from another image and comparing that signature with a database.
TVision relied on Tian’s scientific publication, “Evaluation of Face Resolution for Expression Analysis.” Tian examined how image resolution affects facial expression analysis and described facial detection and pose estimation techniques using reduced resolution images.
TVision argued that Tian and the challenged patent were in the same field because both involved image analysis for head detection and pose estimation. Nielsen responded that Tian concerned facial expression analysis, while the patent concerned audience measurement. The Board did not resolve the field of endeavor issue. Instead, it found Tian reasonably pertinent and held the challenged claims unpatentable.
Reasonable Pertinence: On appeal, the Federal Circuit considered whether the Board properly reached the reasonable pertinence theory and whether substantial evidence supported its determination that Tian was analogous art.
Nielsen argued that the Board violated the Administrative Procedure Act (APA) because the petition invoked the field of endeavor prong without expressly presenting a reasonable pertinence theory.
The Federal Circuit disagreed. Although the two analogous art prongs are separate tests, the evidence supporting them may overlap. TVision’s evidence that Tian involved image analysis for head detection and pose estimation related both to the asserted field and the patent’s problems.
Relying on Corephotonics, Ltd. v. Apple Inc., 84 F.4th 990 (Fed. Cir. 2023), the Court explained that an analogous art theory may be implicit. A petition’s discussion of the claims, prior art, and reasons to combine may provide notice of reasonable pertinence even when that theory is not separately articulated.
The record also showed that Nielsen addressed both prongs in its Patent Owner Response. Nielsen did not identify evidence or arguments it would have presented with explicit notice. The court therefore found no APA violation.
Expressly addressing both prongs remains safer, but a patent owner may have difficulty defeating an analogous art determination based only on the petitioner’s failure to label its theory.
Relevant Problem: Nielsen also argued that the Board defined the inventor’s problem too broadly. Nielsen asserted that frequent activation of illumination sources could drain power, generate heat, shorten equipment lift, and annoy audience members.
The Court declined to limit the analysis to that formulation. The problems facing an inventor are not limited to those expressly identified in the specification, and a patent may address multiple problems.
The challenged claims did not recite an illumination source. They instead addressed image processing, including resolution reduction, head orientation determination, and facial analysis. The Court concluded that the relevant problem was therefore not limited to illumination when the claims reached broader image processing problems.
Tian was reasonably pertinent to those problems because it examined facial analysis using reduced resolution images and addressed face detection and pose estimation. Its teachings therefore would have drawn the attention of someone confronting image processing and facial detection problems.
Takeaways
Nielsen provides useful guidance for IPRs, ex parte reexaminations, and prosecution.
For IPR petitioners and ex parte reexamination requesters, the safer approach is to address both analogous art prongs expressly and connect each reference’s features, purposes, and problems to the challenged claims. Although Nielsen permits an implicit theory, expressly presenting the theory gives the Board or Examiner a clearer basis for finding the reference analogous.
For patent owners, relying on a challenger’s failure to label a theory may not be enough. A patent owner should address both prongs, identify the field and problems reflected in the claims and disclosure, and explain why a skilled artisan would not have consulted that reference.
For prosecutors, Nielsen underscores the relationship between claim scope and analogous art framing. Defining the technical field and problem narrowly may help distinguish prior art but may also conflict with the broader claim scope desired for infringement. Prosecutors should also consider whether the claims align with the identified field and problem.
The principal takeaways are that an analogous art theory may be implicit and the relevant problem may extend beyond what is emphasized in the specification. Parties should therefore address both prongs expressly, while grounding the asserted field and relevant problems in the claims, disclosure, and prior art.
[1] 25-1371: NIELSEN COMPANY (US), LLC v. TVISION INSIGHTS, INC. [OPINION], Precedential
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