How is the doctrine of equivalents applied in patent infringement cases?

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Source: FAQ (MPEP-Based) BlueIron Update: 2024-09-29 10 Rules 5 Related FAQs This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice. The application of the doctrine of equivalents in patent infringement cases involves a specific inquiry. According to MPEP 2186 , the essential objective inquiry is: “Does the accused product or process contain elements identical or equivalent to each claimed element of the patented invention?” This inquiry, established in Warner-Jenkinson Co. v. Hilton Davis Chemical Co. , focuses on comparing the elements of the accused product or process with those of the patented invention to determine equivalence. Related Rules from the Manual of Patent Examining Procedure 10 rules Collapse Infringement Under Doctrine of Equivalents Must Match Function, Way, and Result MPEP 2186 Means-Plus-Function Claims Must Be Equivalent to Specified Means MPEP 2186 Required Infringement by Equivalent Elements MPEP 2186 Permitted Infringement by Equivalent Elements MPEP 2186 Infringement by Equivalent Elements MPEP 2186 Equivalence Determination for Infringement MPEP 2186 Means-Plus-Function Claims Must Be Equivalent to Specified Means MPEP 2186 Equivalents Not to Influence Means-Plus-Function Determination MPEP 2186 Recommended Role of Elements in Determining Equivalence MPEP 2186 Each Claim Must Include All Described Essential Elements MPEP 2163 Required Other Related FAQs 5 FAQs Collapse How does 35 U.S.C. 112(f) relate to the doctrine of equivalents? How does the doctrine of equivalents affect patent examination? What is the doctrine of equivalents in patent law? What is the function-way-result test in the doctrine of equivalents? How does an examiner handle new matter in a patent application?