Opinions — Tuesday, July 21, 2026

In Maxeon Solar PTE. Ltd. v. Canadian Solar, Inc., Appeal Nos. 2026-1500 and 2026-1525 (consolidated appeals from IPR2024-01039), the Federal Circuit granted Maxeon's unopposed motion to voluntarily dismiss its appeal in No. 2026-1500, deconsolidated the two appeals, and ordered each party to bear its own costs. The court directed that the opening brief in the remaining appeal, No. 2026-1525, is due within 60 days of the order's entry, and issued mandate immediately as to the dismissed appeal.

The Federal Circuit affirmed two IPR final written decisions holding claims of Dental Monitoring's U.S. Patents 11,049,248 and 11,109,945 unpatentable as obvious. The patents relate to methods for evaluating orthodontic aligner shape using image analysis—the '248 patent claims recite analyzing images via a "deep learning device" to determine tooth-aligner separation, while the '945 patent claims recite acquiring images of teeth with and without aligners, determining tooth outlines via image processing software, and computing a separation score. The Board found the claims obvious over combinations of prior art references including Kim, Invisalign materials, Salah, and Maninis, relying on testimony from Align's computer science expert Dr. Foroosh.

The court applied substantial evidence review to the Board's factual findings on prior art disclosures and public accessibility, and abuse of discretion review to the expert qualification determination. Rejecting Dental Monitoring's individual attacks on each reference, the court emphasized that obviousness analysis focuses on the combined teachings and that attacking references individually cannot defeat combination-based rejections. The court found substantial evidence supporting the Board's conclusions that: the references in combination taught each disputed limitation; Salah did not teach away merely by stating deep learning was "not preferred" while acknowledging it "could be used"; archived website snapshots and expert testimony established Maninis's pre-critical-date public accessibility; and Dr. Foroosh's advanced computer science degree and machine learning experience qualified him as a person of ordinary skill despite lacking specific dentistry credentials.

The Federal Circuit affirmed the Board's determination that Keysight failed to meet its burden to show claims 6, 14, 22, 30, and 33 of Centripetal's U.S. Patent 11,012,474 would have been obvious. Keysight's IPR petition included only a table and a header asserting that these claims were unpatentable over Law and Golnabi, but provided no claim-by-claim analysis or argument explaining how each element was obviated by the prior art—in contrast to every other challenged claim, which received specific elemental analysis.

The court applied abuse of discretion review to the Board's determination that Keysight's petition failed to adequately address these claims under 35 U.S.C. § 312(a)(3) and 37 C.F.R. § 42.104(b)(4), which require particularity in identifying how each claim is unpatentable. Distinguishing In re NuVasive, where a petition gave at least minimal notice despite imperfect clarity, the court found Keysight "failed entirely even to address the unpatentability" of the claims at issue. The court rejected Keysight's argument that the Board acted arbitrarily by reaching a different conclusion in its Final Written Decision than at institution, reaffirming that the Board may change its view after record development and is entitled to maintain pleading standards even where claims may be "plainly unpatentable."

The Federal Circuit vacated and remanded the PTAB's determination that Apple failed to prove claims 1, 2, 4, 6–9, 11, 24, and 29 of Zentian's U.S. Patent No. 10,839,789 unpatentable. The '789 patent covers speech recognition systems, and the dispositive issue on appeal concerned whether the prior art—specifically Smyth alone or in combination with Mozer—disclosed storing an "acoustic model memory" on a single integrated circuit with a calculating apparatus, as required by claim 1.

The court held that the Board committed legal error by effectively construing "acoustic model" to require a large-vocabulary model when the claim language would encompass a smaller "abbreviated model" such as a digits recognizer, which Zentian conceded would satisfy the claims. The Board also erred in concluding that the claims required the skilled artisan to personally fabricate the integrated circuit, rather than simply use known prefabricated circuits with appropriate specifications; the court found this interpretation improperly incorporated an unclaimed fabrication step. On remand, the Board must determine whether Mozer's 4,000-byte on-chip memory could store an abbreviated acoustic model in combination with Smyth's teachings, a factual question the Board did not address due to its erroneous claim construction.

The Federal Circuit vacated the district court's grant of summary judgment of noninfringement in favor of LifeCORE Fitness and remanded for further proceedings in Woodway USA, Inc. v. LifeCORE Fitness, Inc. The case involved three related patents directed to manual treadmills with curved running surfaces and safety devices. The central issue was whether the district court erred in construing the claim limitation "substantially preventing movement of the running belt in a second direction" to require complete prevention of rotation in the dispreferred direction, which formed the basis for the noninfringement ruling.

The Federal Circuit held that the district court improperly deviated from the plain and ordinary meaning of "substantially" as a term of approximation meaning "largely but not wholly" and incorrectly found prosecution history disclaimer. Reviewing claim construction de novo, the court rejected the district court's finding that prosecution statements distinguishing prior art references (Bostic and Savettiere) constituted clear and unmistakable disavowal of any bidirectional belt movement. The court emphasized that where alleged disavowals are amenable to multiple reasonable interpretations—here, statements that could be read as distinguishing whether the safety device affected belt movement at all, rather than the degree of restriction—prosecution disclaimer does not attach. The court also noted that construing "substantially prevents" to mean complete prevention would render the word "substantially" superfluous, contrary to claim construction principles favoring interpretations that give meaning to all claim terms.

The Federal Circuit affirmed the PTAB's determination that claims 1–7, 9, 10, 20–22, and 24 of Slingshot Printing's U.S. Patent No. 7,152,951—directed to a high-resolution inkjet printhead with a thick film layer and high-density nozzle pitch—are unpatentable as obvious over Hamafuku, Whitman, and Imanaka. Slingshot argued the Board erred by declining to construe "thick film layer" despite a dispute over whether it required a polymer material, contended that Imanaka's disclosure of silicon-based materials taught away from the combination, and challenged the Board's reasonable-expectation-of-success finding as relying on improper hindsight from the patent itself.

The court's analysis centered on procedural waiver and the substantial evidence standard. The Federal Circuit held that claim construction was unnecessary because Slingshot had not contested that the prior art disclosed a "thick film layer," recharacterizing Slingshot's construction argument as a challenge to the motivation-to-combine findings. The court declined to reach the teaching-away issue because Slingshot had not separately argued it below, only a general lack of motivation to combine, and noted that while related, the two inquiries are distinct. The court found substantial evidence supported both motivation and reasonable expectation of success through expert testimony that the combination would be "straightforward" and "would work," and found any improper reliance on the challenged patent itself to assess mechanical strength was harmless given other record support.