Once you have a patent, you have powerful legal tools on your side to combat infringement upon your patent rights. This article answers some of the most frequently asked questions about patent enforcement.

Q: What Rights Do I Have as a Patent Owner?

A patent is basically a government awarded monopoly for an invention. The patent grants what's known as a negative right (or right to exclude): no one else can create, use, sell, or import your invention for any purpose without your consent.

If anyone violates the patent, you can bring an enforcement action and a court can issue an injunction preventing the other party from continuing their actions and award damages (see below for remedies).

Q: How Long Do Patents Last?

Today, patents last 20 years from the filing date of the application. For patents that existed before June 8, 1995, the duration of the patent was 17 years from the issuance of the patent or 20 years from the filing date, whichever was longer. Design patents are limited to 14 years from the date of issuance, while plant patents last 17 years from the date of issuance.

Patents can also expire if patent holders don't make their regularly scheduled maintenance fees to the USPTO.

Q: What are My Rights During the Patent Application Process?

Before the patent application: The only circumstance where you would have a legal ground to stop others from creating, using, or selling the same or similar invention would be under trade secret law.

Trade secrets are protected under state law, which is designed to protect business or technical information of any sort that provides value. The only requirements are that the secret have value and that the owner takes steps to keep it confidential.

After you've submitted your patent application: Once your application has been submitted to the USPTO, you can stamp all your products and marketing material as "Patent Pending." The patent pending designation serves as a warning that others' use of your invention may have serious consequences once the patent is approved.

Patent approved: After a patent has been approved, the patent owner has a limited-time monopoly on the creation, use, sale and importation of the invention. Owners have the right to sue anyone who makes, uses, or sells the invention without the owner's consent for patent infringement. These rights last 20 years from the date of the application.

If another invention is found to infringe upon the patent, courts can issues injunctions and award large damages, particularly for "willful" infringers (those who knew of the patent, should have known they were infringing, and did it anyway).

After a patent expires: Once a patent expires, so do the exclusive rights of the patent holder. At this point, anyone can use, sell, and import the invention as they please. Patent infringement lawsuits can still be filed, however, for infringement that occurred during the life of the exclusive patent.

Q: How is Patent Infringement Determined?

Patents are made up of "claims," which are different elements that make the invention unique. "Prior art" is a term that refers to any document, or article that was available to public before the date of priority of the application.

• Literal Infringement. If you take all of the claims of a prior art and add elements, you are still infringing. On the other hand, if you take some, or even most, elements of a prior art, then you are not infringing.
  
• Doctrine of Equivalents. Courts found that limiting infringement to only literal infringement was very restrictive (and often unfair) and came up with this doctrine to combat substantially similar inventions. The basic rule is that patent holders can claim infringement if:
  • the accused device performs substantially the same function,
  • in substantially the same way,
  • to obtain the same result.

Courts prevent patent owners from going back and claiming protection for claims that they had to give up during the application stage. If the patent owner can prove, however, that the amendment was made for a reason other than avoiding prior art and it was not meant to be surrendered, then the owner can a still argue infringement under the Doctrine of Equivalents.

Q: What Happens During a Patent Infringement Case?

After a patent owner brings an infringement case, the accused infringer has a number of defenses. They can argue that the patent was "disclosed" over a year prior to the patent application, that the accused device doesn't actually infringe, or that the patent is invalid.

The most common defense to a patent infringement lawsuit is that the patent was wrongly approved by the USPTO and is therefore invalid. Accused infringers will attack each of the 5 requirements for a patent (patentable subject matter, utility, novelty, non-obviousness, and prior disclosure).

If a patent is determined by a court to be invalid, the patent holder loses all exclusive rights to the invention.

Have More Questions About Patent Enforcement? Talk to an Attorney

Just having your idea patented is no guarantee that it'll be protected, particularly if you don't know that your idea has been stolen. If you need help with patent enforcement or want to learn more about protecting your inventions, you should reach out to a local intellectual property lawyer who can help conduct research, prepare filings, and answer questions along the way.