Have you ever seen a patent notice like “U.S. Patent Pending” or “U.S. Patent No. 1234567” and wondered about its implications? Could it be used to scare off potential competitors, or does it have some deeper legal importance? Under federal law, which governs all things patent, patent marking actually plays an important role in patent infringement suits. This article reviews the reasons for marking a product with a patent, the kinds of markings that are legally sufficient under the law, and the practical implications for patent owners and possible infringers alike.
A patent marking is legally relevant. Not just a deterrent, it serves to provide constructive notice to a potential infringer that the item is patented or patent pending. This means that the law imputes notice to an infringer, even if the infringer never actually saw the patent marking. Notice of some kind is required under United States Code, Title 35, section 287 before a patent holder may bring an infringement action. There are two kinds of notice: actual and constructive. Actual notice occurs when someone tells an infringer about their infringement, like, for instance, when a patent holder sends a demand letter. Constructive notice occurs when a patent holder properly marks their patented product. If infringement occurs after either of these events, the infringement is actionable in federal court.