The U.S. Court of Appeals for the Federal Circuit’s recent decision in Range of Motion Products v. Armaid is another reminder that, if care is not taken, design patent scope can be narrowed significantly in the U.S. through functionality analysis—often at the claim construction stage—and even result in summary judgment of non-infringement. 

In Armaid, the majority affirmed non‑infringement after classifying key aspects of the claimed design—most notably the shape of the extending arms of the relevant massaging device—as functionally driven, relying on utility patent disclosures, inventor testimony, and even marketing materials touting functional advantages. Once those features were treated as largely functional through a claim construction analysis, the court characterized the remaining ornamental scope as “narrow” and concluded that the accused product was “plainly dissimilar” thereto, and therefore non-infringing.

Chief Judge Moore’s dissent highlighted a deeper concern that should resonate with product and IP teams: the Federal Circuit’s framing of infringement around whether designs are “plainly dissimilar” risks turning inherently visual, fact‑intensive questions into judge‑decided exercises focused on differences rather than overall consumer impression.  Combined with aggressive functionality “filtering,” that framing can materially weaken design protection for products where form and function are inevitably intertwined – which is in fact all products that are eligible for design patent protection.

Setting aside the majority’s misguided approach with respect to application of the plainly dissimilar standard for making a non-infringement determination at the summary judgment stage of litigation, there is a better path on functionality during claim construction—one already articulated internationally. The AIPPI 2016 Resolution on design protection draws a clear line between technical functionality and ornamentation, while recognizing that designs often include “functional” features that still contribute to overall visual appearance. Under that approach:

• Design protection is denied only when the appearance as a whole is dictated solely by technical function.
• Portions of an article which perform a function are not excluded from the scope of protection; they may be given less weight, but their visual contribution to the overall design is never “filtered” or removed from the assertible scope of protection.  

For design patent applicants, the takeaway is practical and immediate: U.S. design rights are increasingly sensitive to how functionality is documented, marketed, and litigated. More broadly, the Federal Circuit should once again revisit its functionality jurisprudence and move toward an AIPPI‑aligned standard that preserves meaningful design protection without granting backdoor utility monopolies. Until then, design portfolios—and the messaging around them—deserve especially careful stewardship.

The Quarles design rights legal team is nationally-recognized for its extensive knowledge and practice experience in this complex and important field. For questions about this article or on how to incorporate design-related legal rights into your intellectual property portfolio, please contact the author(s) of this post directly or send a message to the team via our Contact page. To subscribe to our mailing list and receive updates that highlight issues currently affecting the design rights legal field, click here.