Patent Litigation

Patent litigation is the legal process that unfolds when someone who owns the patent for a particular invention enforces their right by suing another for manufacturing or selling the invention without permission. More often than not, this claim is countered by the accused party who will argue that that particular patent should be deemed invalid.

Typically, a party (other than the patentee or licensee of the patentee) that manufactures, imports, uses, sells, or offers for sale patented technology without permission/license from the patentee, during the term of the patent and within the country that issued the patent, is considered to infringe the patent.

The test generally requires that the infringing party’s product (or method, service, and so on) falls within one or more of the claims of the patent. The process employed involves “reading” a claim onto the technology of interest. If all of the claim’s elements are found in the technology, the claim is said to “read on” the technology; if a single element from the claim is missing from the technology, the claim does not literally read on the technology and the technology generally does not infringe the patent with respect to that claim, except if the doctrine of equivalence is considered applicable.

In response to allegations of infringement, an accused infringing party typically asserts one or more of the following:

  • that it was not practicing the patented invention, i.e. the invention claimed in the patent (the claims define the extent of protection conferred by a patent);
  • that it was not performing any infringing act in the territory covered by the patent (patents are indeed territorial in nature);
  • that the patent has expired (since patents have a limited patent term, i.e. a limited lifetime);
  • that the patent (or the particular claim(s) alleged to be infringed) is invalid, because the invention in question does not meet the patentability requirements or includes a formal defect, this rendering the patent invalid or unenforceable;
  • that it has obtained a license under the patent.

It’s the aim of the court to get both sides to come to a written agreement. Quite often this will result in the losing party, if countering a claim of copyright infringement, paying royalties to the winning side in order to continue using a patented invention.


Chiacchio IP is an active contributor to industry literature. We also give frequent presentations on topics relating to business patents and other intellectual property.