Patent infringement

A patent provides the proprietor of that patent with the right to exclude others from utilizing the invention claimed in that patent. Should a person utilize that invention, without the permission of the patent proprietor, they may infringe that patent.

Elements of patent infringement

Any party that manufactures, uses, sells, or offers for sale patented technology, 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 infringer’s product (or method, service, etc) falls within one or more of the claims of the granted patent. In the United States and others that use a “peripheral claiming”, that means that the infringing technology embodies each and every of the elements listed in the claim. If the technology incorporates all of a claim’s elements (and possibly more) it is said to “read on” the claim; if a single element from the claim is missing from the technology it does not read on the claim and thereby does not infringe the patent with respect to that claim.

To defend a claim of infringement, an accused infringer generally will assert one or more of the following:

  • The patent, and in particular the individual claims asserted against the infringer, are invalid because they were not novel, or were obvious in light of the state of the art, at the time patented. Often this is done by presenting evidence not originally considered by the patent office that the invention had been publicly disclosed or was in use before it was patented.
  • The patent is invalid due to some other collateral defect to make the patent invalid or unenforceable.
  • The technology in question does not in fact practice the patent
  • The accused infringer has obtained a license to the patented technology
  • The patent holder is infringing patent rights belonging to the accused infringer (this is not an actual defense to the infringement claim but it is a very common legal strategy that often results in a cross-licensing agreement rather than an infringement lawsuit).