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Infringement

Definition

The unauthorized making, using, selling, or importing of a product or process that falls within the scope of a valid patent's claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →. InfringementinfringementMaking, using, selling, or importing a patented invention without permission from the patent holder.Read more → is determined by comparing each element of a patent claimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → to the accused product or process. If every element is present — literally or under the doctrine of equivalentsdoctrine of equivalentsExtends infringement beyond the literal claim language — if a competitor's product does substantially the same thing in substantially the same way, it can still infringe.Read more →infringement exists.

Where this comes up

Patent InfringementClaim Chart / FTO

In practice

Patents that use “Infringement

See the concept in real landmark patents, each explained in plain English.

Related terms

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Claim

The numbered sentences at the end of a patent that define exactly what is legally protected. Claims are the only part of a patent that determine infringement — if a product or process doesn't fall within the scope of at least one claim, there is no infringement. Every other part of a patent (abstract, drawings, specification) exists to support and illuminate the claims.

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Doctrine of equivalents

A legal doctrine that extends patent protection beyond the literal scope of the claims. Even if a competitor's product doesn't literally include every element of a claim, infringement may still exist if each claim element is performed by a substantially similar function in a substantially similar way. Courts apply this doctrine to prevent competitors from making trivial changes to avoid literal infringement.

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Claim chart

A side-by-side comparison table mapping each element of a patent claim to a specific feature in an accused product or prior art reference. Claim charts are used in infringement analysis, licensing negotiations, and patent litigation. They make it visually clear which claim elements are met (or not met) by the thing being compared.

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Claim construction

The legal process of interpreting what a patent claim means — specifically, the scope of each term in the claim. In litigation, judges perform claim construction in a "Markman hearing" before deciding infringement. Claim construction is often the most consequential step in patent litigation: a narrow construction can defeat infringement, while a broad one can invalidate the claim.

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Declaratory judgment

A lawsuit in which a company that fears being sued for infringement asks a court to rule first — typically that it does not infringe, or that the patent is invalid. It lets an accused party control the timing and forum instead of waiting to be sued.

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Freedom to operate (FTO)

A legal opinion assessing whether a product, process, or service can be commercialized without infringing any valid, in-force patents held by others. FTO searches are typically conducted before launching a product. An FTO opinion does not guarantee safety from infringement claims, but a good-faith, well-documented FTO analysis can reduce willfulness damages if litigation occurs.

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