What Is Direct vs. Indirect Infringement of Patents?

Product and process innovations are often at the heart of business value creation. As a business introduces new products and or enters new markets, the business may evaluate the landscape of existing patents to assess risks of infringement. Likewise, a business may evaluate and/or monitor products and services introduced by other parties, such as competitors, to determine whether these other parties have exposure to patents owned by the business, and evaluate enforcement opportunities accordingly.

Patent claims set forth in an issued patent define specific details of an invention to which an exclusive right is granted in the issued patent. The US patent statute defines under different sections how parties may infringe patent based on specific actions taken by a party to perform all or a portion of the elements of such a patent claim. Additionally, the US patent statute defines an extent to which one party may be an enabler of another party’s infringement so as to be “vicariously” liable for the infringement.

To directly infringe a patent, a party would make, use, offer to sell or sell a patented invention without permission. Such an act of infringement does not require that the accused product or service is an exact copy of a product or service offered by a holder of a patent provided that the accused product or service meets all of the elements of a claim in the infringed patent.

A party may indirectly infringe a patent if that party acts in some manner to enable and/or encourage acts by another party to directly infringe the patent. The US patent statute defines two types of indirect infringement, contributory infringement, and infringement by inducement. A party may be liable for contributory infringement by selling a product that does not have any substantial non-infringing use, even if that product does not meet all of the elements of a claim so as to directly infringe. Similarly, a party may be liable for infringement by inducement if that party actively induces another party to act in a manner so as to directly infringe a patent. Doctrines of indirect infringement may provide opportunities to enforce a patent against parties in a supply chain when enforcement against direct infringers is impractical. For example, while a kit to assemble an infringing product sold to consumers may not directly infringe a patent, indirect infringement may provide an opportunity to enforce the patent against the maker or seller of the kit when enforcement of the patent against individual customers for direct infringement is impractical.

A business should understand that acts to infringe a patent do not require advance knowledge of the patent and that a party may be liable as an “innocent” infringer. Nonetheless, an infringing party may be subject to enhanced damages if acts to infringe give rise to willful infringement if infringing acts are performed with knowledge of the infringement and/or intent to infringe.

The US patent statute defines acts of literal infringement in which such acts result in performing each element of a claim as construed by a Federal court. In construing claim language in a patent, a Federal court may consider description and drawings in the patent, as well as extrinsic evidence such as ordinary definitions or expert testimony. In certain circumstances, a Federal court may find liability for infringement under a so-called doctrine of equivalents if there is “equivalence” between elements of an accused product or process and claim elements as construed, even if the alleged acts of infringement do not result in each claim element as construed being literally performed.

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