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What is a patent? 

A patent is an exclusive right granted for an invention, which is a product or a process that provides a new way of doing something, or offers a new technical solution to a problem.  A patent provides protection to the patent owner for a limited period, generally 20 years.

What is patent infringement?

Infringement is an encroachment upon the intellectual property or domain belonging to a patentee that is described by the claims of the patent. Like real property, intellectual property has boundaries: the claims of the patent are the boundaries of the intellectual property. Whereas invasion onto a landowner’s property constitutes the tort of “trespass,” invasion of a patent holder’s intellectual property (as defined by the claims) is called “infringement.”

Patent infringement is governed by a federal law, and infringement suits must therefore be brought in federal court. Our attorneys are admitted to practice in numerous federal jurisdictions, including the Southern District of New York, Eastern District of New York, Northern District of New York, and District of New Jersey.

How is patent infringement determined?

Determination of patent infringement is a two-part process. First, the court analyzes the patent claims to determine the scope of the patent. This process may require ordering the prosecution history of the patent and studying relevant documents. Second, the court looks at the accused infringing item to see if it contains every single element in the claim. If one or more elements set forth in a claim is not present, there is not literal infringement of that claim. On the other hand, if each element that is set out in even one claim of the patent is present in the accused item, then direct and literal infringement has occurred.

When the claims of a patent are read against an accused practice, they may be so close to identical that infringement is clear. Also, the accused practice may be so remote from the patent that there is no possibility of infringement. Very often, however, there are some differences, requiring further study. Sometimes, such differences are incorporated into a design after knowledge of a patent in an effort to avoid infringement. Then, the question presented is whether the accused device is sufficiently different from the patent to be held to be non-infringing. If it is too close to the claimed invention—but not identical—it will infringe under the doctrine of equivalents (DOE).

The DOE allows a patent owner to bring an infringement claim even if the patented item is not identical to the infringing item. What constitutes equivalency must be determined against the context of the patent, the prior art, and the particular circumstances of the case. There are two frameworks for evaluating equivalence: the function-way-result or “FWR” test (whether the accused product performs “substantially the same function in substantially the same way to obtain the same result”) and the insubstantial differences test (whether the accused product or process is substantially different from what is patented).

Who is liable for patent infringement?

  • Anyone who makes, uses or sell a product that reads upon a patent, either directly or the equivalent, is liable for patent infringement.
  • A person who actively encourages another to make, use, or sell the invention is liable for indirect infringement.
  • A person who knowingly sells or supplies an item for which the only use is in connection with a patent invention is liable for contributory infringement.
  • Good faith or ignorance is not a defense to direct infringement, but it can be a defense to indirect or contributory infringement.

What are the remedies for patent infringement?

Possible remedies for patent infringement are:

  • Injunctive relief
  • Money damages (including treble damages for willful infringement)
  • Attorneys’ fees

If you are a patent owner or if you are being accused of patent infringement and require a patent infringement attorney, please email us at or call to speak to one of our attorneys.