If you or your business have filed for and obtained a patent for your invention, you now have the right to prevent another person or entity from making, using, offering to sell, or selling something that contains every element of one or more of your patented claims (or its equivalent) while the patent is in effect. The owner of a patent may be referred to as a patent owner, patent holder, or patentee.

For patent infringement to occur, the action that infringes your patent rights must take place in the United States, or an infringing product must be imported into the United States after being created abroad. See 35 U.S.C. §271.

Direct Patent Infringement

Direct patent infringement occurs when a person or entity makes, uses, offers to sell, or sells any patented invention within in the United States, or imports a patented invention into the United States during the term or life of the patent.

Willful Patent Infringement

Willful patent infringement is a form of direct patent infringement. If a court determines that a person or entity sued for patent infringement willfully (intentionally or knowingly) infringed a patent, the court may increase the damages awarded to the patent holder by up to three times the amount of actual damages (lost sales, etc.).

To prove willful patent infringement, a patent holder must show by a “preponderance of the evidence” (more likely than not) that the defendant intentionally or knowingly infringed the patent.

Literal Infringement

Literal infringement is a form of direct patent infringement and occurs when the product or device accused of infringing the patent holder’s patent includes each and every one of the parts of the patent that were granted protection (the protected claims).

Doctrine of Equivalents Infringement

Doctrine of Equivalents infringement is another form of direct patent infringement that occurs when the product or device accused of infringing the patent holder’s patent includes each and every one of the parts of the patent that were granted protection (the protected claims), with some insubstantial or minor differences. In such a case, the court may determine that the differences between the patented product or device and the product or device accused of infringing it are so insubstantial or minor that they are equivalent products or devices and therefore there is infringement of the patent.

Indirect Infringement

Indirect infringement—also known as secondary liability—is infringement committed without the knowledge of the infringer and includes induced infringement and contributory infringement.

Induced Infringement

Induced infringement—a form of indirect infringement—occurs when the infringer induces others to commit direct patent infringement—such as by selling a product with advertising or instructions that, when followed, constitute direct patent infringement by the persons or entities who followed the instructions.

A plaintiff suing for patent infringement based on induced infringement generally must prove the defendant was aware of the patent and intended to induce the end users of the product or device to directly infringe the patent. The plaintiff suing for patent infringement may rely on circumstantial evidence or proof (inferred from the circumstances) that the person accused of inducing infringement (1) was aware of the patent and (2) knew that their activities in advertising or instructing the use of the product, for example, would lead to the end-user’s direct infringement of the patent.

Contributory Infringement

Contributory infringement is another form of indirect patent infringement and occurs when a person or entity contributes or potentially contributes to direct patent infringement committed by another person or entity. Liability for contributory infringement is based on the federal statute located in the United States Code at 35 U.S.C. §271(c).

In South Dakota, as in all states across the U.S., patent holders are granted exclusive rights under federal law, specifically under Title 35 of the United States Code. These rights allow them to prevent others from making, using, selling, or importing their patented invention without permission. Direct infringement occurs when these exclusive rights are violated, and willful infringement, which is deliberate and intentional, can result in enhanced damages up to three times the actual damages. Literal infringement happens when an infringing product includes all elements of the claim in the patent. The Doctrine of Equivalents extends protection beyond the literal terms of the claims to cover products that are substantially similar to the patented invention. Indirect infringement encompasses both induced infringement, where someone actively encourages another to infringe a patent, and contributory infringement, where someone offers or sells a component that is specially made for use in a patented invention, knowing it will lead to infringement. For indirect infringement, there must be proof that the infringer knew of the patent and intended to cause infringement. It's important to note that while these principles are based on federal patent law, enforcement and litigation take place in federal courts, and state laws do not alter these federal patent rights.