North Carolina Court Puts Design Patent Claim to Bed

By Kelsey Nix and Jonathan Lewis

A federal court in North Carolina recently put a mattress-topper design patent case to bed, dismissing the lawsuit at the pleadings stage after concluding that the accused product was “plainly dissimilar” from the patented design. The decision in Viscosoft, Inc. v. Hangzhou Heliang Network Technology Co., Ltd. underscores that courts can resolve design patent disputes early when visual differences are clear—and that plaintiffs who pursue weak infringement claims may risk sanctions. The case offers a useful reminder of how courts apply the “ordinary observer” test and when design patent complaints may fail as a matter of law.

Court Dismisses Design Patent Claim at the Pleadings Stage

The Western District of North Carolina granted the defendant’s motion for judgment on the pleadings on February 24, 2026. The court also granted the defendant’s motion for judicial notice and reserved ruling on a request for sanctions pending a hearing. Viscosoft, Inc. v. Hangzhou Heliang Network Technology Co., Ltd., No. 3:25-cv-00601-kdb-dck, 2026 WL 510573 (W.D.N.C. Feb. 24, 2026).

Viscosoft, Inc. sued Hangzhou Heliang Network Technology Co., Ltd. (“HHNT”) for infringing U.S. Design Patent No. D969,522, “Design Pattern for Mattress Topper” in August 2025. Slip op. at *2. Less than a month later, counsel for HHNT wrote to plaintiff’s counsel, demanding dismissal of the case and threatening to seek sanctions for frivolous infringement allegations. Id.

The Ordinary Observer Test

A design patent protects a “new, original and ornamental design for an article of manufacture.” 35 U.S.C. § 171(a). Unlike a utility patent, a design patent protects only the ornamental design of an article, not its functional elements. To determine whether a design patent is infringed, courts use the “ordinary observer test”—viz., whether an ordinary observer would see the patented and accused designs as substantially similar. Egyptian Goddess, Inc. v. Swisa, Inc., 543 F.3d 665, 670 (Fed. Circ. 2008).

HHNT requested the Court to dismiss the case under Federal Rules of Civil Procedure 12(b)(6) and 12(c). Slip op. at *1. A Rule 12(b)(6) dismissal for failure to state a claim is warranted with a complaint is legally and factually insufficient. Slip op. at *1. On the other hand, a Rule 12(c) motion is a request for judgment on the pleadings; both rules require the Court to assume all facts and reasonable inferences in the non-movant’s favor. Id. Undisputed facts may be used to show that judgment on the pleadings is appropriate, and the motion is treated as summary judgment, if there are no outstanding issues. Slip op. at *1–2.

The Court granted the defendant’s motion for judgment on the pleadings, finding the accused product was “plainly dissimilar” from the asserted patent. Slip op. at *4. Using the commonsense adage, “a picture is worth a thousand words,” the Court described some of the differences between the asserted and accused mattress topper designs. Id.

Among the dissimilarities, the Court noted the top of the topper in the asserted patent has dots, while the top of the accused product has “quilted rods or rectangles.” Additionally, the bottom of the asserted patent’s topper has a “honeycomb” design, while the bottom of the defendant’s product has spaced dots. Id. As a result, the defendant could not infringe as a matter of law.

’552 Patent (top):	Valuxe Topper (top, enlarged):
’552 Patent (bottom):	Valuxe Topper (bottom, enlarged):

^{Source: First Amended Complaint ¶ 17, No. 3:25-cv-00601-kdb-dck (W.D. N.C. Sept. 18, 2025).}

The plaintiff argued that judgment on the pleadings was inappropriate because infringement is a question of fact. Id. However, courts can dismiss design patent complaints when, as a matter of law, no reasonable fact finder could find infringement. Id. The Court went further, also granting the defendant’s motion for judicial notice of prior art patents. In fact, the Court noted that it did not need to consider the prior art patents cited during prosecution of the asserted patents. Nevertheless, the Court ruled in favor of defendant HHNT, just in case the cited patents “become relevant in further proceedings.” Slip op. at *5.

Court Signals Possible Sanctions

Because the comparison of the patented and accused mattress toppers “leads to the conclusion that Plaintiff’s claims lack merit,” the Court found the need to “seriously consider the imposition of sanctions ….” Id. Although it deferred ruling until holding a hearing, the Court may impose sanctions if the plaintiff cannot show a good faith basis for filing and continuing pursuit of the case after receiving the defendant’s letter.

The sanctions hearing is set for March 24, 2026.

Key Takeaways for Businesses:

• Although design patents can be powerful weapons to protect a product with a unique design, plaintiffs should only assert design patents against accused products that are plausibly substantially similar and satisfy the ordinary observer test.
• Surviving a Rule 12(b)(6) motion to dismiss for failure to state a claim may not be enough to overcome a Rule 12(c) motion for judgment on the pleadings when the asserted design patent and accused product design are plainly dissimilar.
• Although only rarely imposed, sanctions may be imposed for complaints alleging patent infringement that are “facially implausible.”

If you have questions related to this Alert or other patent infringement issues, please contact Kelsey I. Nix, Co-Chair of Smith Anderson’s IP Litigation Practice, Jonathan V. Lewis or the Smith Anderson lawyer with whom you currently work.

---

Click here to view a PDF of this Alert.