Freedom to operate

Patent infringement is the commission of a prohibited act with respect to a patented invention without permission from the patent holder. Permission may typically be granted in the form of a license. The definition of patent infringement may vary by jurisdiction, but it typically includes using or selling the patented invention. In many countries, a use is required to be commercial (or to have a commercial purpose) to constitute patent infringement.

The scope of the patented invention or the extent of protection is defined in the claims of the granted patent. In other words, the terms of the claims inform the public of what is not allowed without the permission of the patent holder.

Patents are territorial, and infringement is only possible in a country where a patent is in force. For example, if a patent is granted in the United States, then anyone in the United States is prohibited from making, using, selling or importing the patented item, while people in other countries may be free to exploit the patented invention in their country. The scope of protection may vary from country to country, because the patent is examined -or in some countries not substantively examined- by the patent office in each country or region and may be subject to different patentability requirements.

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 varies from country to country, but in general it 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:

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Wikipedia