Different Types of Patent Infringement

Wealth of Ideas Newsletter, April 2006

Your patent is infringed - but by whom? Patent litigation can only be successful if you know whom to sue. There are different types of infringement, and the direct infringer isn't always the one to sue.

Direct infringement is, of course, making, using, offering to sell, selling or importing into the US an infringing product during the life of the patent without a license from the patent holder.

Indirect patent infringement takes two forms: contributory infringement or inducement to infringe a patent. Patent law states that "whoever actively induces infringement of a patent shall be liable as an infringer" (35 U.S.C. § 271(b)). In other words, a company does not have to infringe a patent directly in order to be sued for patent infringement.

Induced infringement is that which enables the direct infringer to practice the patented intention. This type of infringement can take the form of helping the direct infringer to assemble the patented product; providing instructions that detail how to produce the patented invention; preparing instructions for consumer use; or licensing plans or a process which enable the licensee to produce the patented product or process. The test for induced infringement is whether the inducer has demonstrated active aiding and abetting of the direct infringer's infringing activities.

A contributory infringer is one who "offers to sell or sells within the United States or imports into the United States a component of a patented machine, manufacture, combination or composition, or a material or apparatus for use in practicing a patented process, constituting a material part of the invention, knowing the same to be especially made or especially adapted for use in an infringement of such patent, and not a staple article of commerce suitable for substantial noninfringing use" (35 U.S.C. § 271(c)).

Bringing a successful case against a contributory infringer requires that the plaintiff prove that the defendant sold, offered to sell, or imported a component of a patent apparatus, or a material or apparatus for use in practicing a patented process; that the defendant had knowledge of the patent; and that the component in question has no substantial noninfringing use and constitutes a significant part of the patented invention.

It may seem easier to sue the direct infringer than to attempt to prove indirect infringement, but often, the direct infringers are the numerous end users or consumers who use a product or kit to produce the infringing product themselves, blissfully unaware of the patent(s) they infringe in the process. Suing end-users may be impossible and financially unfeasible, so it may make more sense to bring a lawsuit against those who knowingly induce or contribute to the infringement.