Patent Marking an Invention

Related Ads

By Rich Stim

Affixing the marks “Patent Pending” or “Pat. Pend.” to an invention after a patent application or provisional patent application has been filed, or affixing the patent number after a patent has issued, is known as marking the invention.

The marks “Patent Pending” or “Pat. Pend.” have no immediate legal significance, but they do place potential infringers on notice that, should a patent ultimately issue, they will not be allowed to make, use, or sell the invention without the patent owner’s permission. During the patent pending period, an inventor cannot stop an infringer or collect damages. However, under the new 18-month publication statute (see “confidentiality of patent application”), an inventor whose application is published prior to issuance may obtain royalties from an infringer from the date the application is published. There are two requirements: (1) the application later issues as a patent; and (2) the infringer had actual notice of the published application. (35 United States Code, Sections 122, 154.) An infringer will have actual notice of a publication if he or she sees the published application. This can be accomplished by sending a copy to the infringer by registered mail. Otherwise, the inventor has no rights whatsoever against infringers during the pendency period—only the hope of a future monopoly, which doesn’t commence until a patent issues.

Marking With Patent Numbers

Marking an invention with a patent number (for example, “patent #5,040,387” or “pat. #5,040,387”) after a patent is issued puts infringers on notice that any use of the invention may result in an injunction and damages. If an infringement action is later filed, the patent owner will be able to collect damages from the date he or she began properly marking the invention. By contrast, if the invention is not marked, damages may be collected only from the time the infringer received actual notice (usually a demand letter from the patent owner) or the date the patent infringement suit was first filed, whichever occurred earlier.

Many inventors prefer not to place the patent number on their invention. Why? Because marking the invention makes it easier for a competitor to obtain a copy of the patent and design around it. A competitor may have a much more difficult time locating the patent on an unmarked invention. In an attempt to avoid this problem, some patent holders just use the mark “patent,” without an accompanying number. This doesn’t have any legal clout, however, since this type of notice is not legally sufficient to start the period running for which damages may be recovered. As with an unmarked invention, damages on an inadequately marked invention are recoverable only for the period after the infringer received actual notice, or after the suit was filed.

The American Invents Act

The America Invents Act, passed in Setpember 2011, initiated two changes regarding patent marking:

  • Virtual marking. Virtual marking is the process of using a publicly accessible website to provide a link between a patented invention and its patent number. As of September 2011, this is now considered as sufficiently providing public notice for that patent.
  • Harder to claim false marking defense. It has become common practice for parties to bring a lawsuit claiming (or make a counter claim) that an invention is falsely marked, especially if the mark exists on copies of the invention after the patent has expired. The America Invents Act provides that privately filed false marking claims (those claims not brought by the government) will require proof of competitive injury. Marking with the number of a patent that covered that product but has expired will no longer be considered false marking.