Patent Infringement Analysis
Produces a report evaluating whether an accused product or process infringes asserted patent claims, for litigation counsel, in-house teams, or technical experts.
Prerequisites
Gather before starting:
- Asserted patent(s) — specification, claims, file history, prosecution docs, amendments, office action responses
- Accused product/process — specs, manuals, marketing materials, drawings, schematics, source code, reverse engineering reports
- Prior art — patents, publications, technical standards relevant to the technology
- Asserted claims identified — which independent and dependent claims are at issue
Report Structure
1. Executive Summary
| Element |
Content |
| Overall conclusion |
Qualified: "strong likelihood," "probable," "unlikely," or "no infringement" |
| Per-claim assessment |
Bottom-line for each independent claim and key dependents |
| Recommendations |
Cease / license / litigate / design-around / post-grant proceedings |
| Critical risks |
Willfulness exposure, SOL deadlines, related litigation |
| Key uncertainties |
Ambiguous terms, missing technical info, unsettled legal questions |
2. Patent Overview
- Bibliographic data — number, title, dates (issue/filing/priority), inventors, assignee, family
- Technical field — problem, inventive concept, advantages over prior art
- Prosecution highlights — amendments, narrowing arguments, disclaimer/estoppel, canceled claims
- Asserted claims — dependency relationships, selection rationale
- Patent status — litigation history, post-grant proceedings, terminal disclaimers
3. Claim Construction
Apply Phillips v. AWH Corp. framework for each disputed term:
| Source |
Analysis |
| Claim language |
Ordinary meaning to POSITA; context from surrounding claims |
| Specification |
Definitions, "as used herein," lexicography, consistent usage |
| Prosecution history |
Amendments, distinguishing arguments, disclaimer/estoppel |
| Claim differentiation |
Presume different claims have different scope |
| Extrinsic evidence |
Expert testimony, dictionaries — less weight than intrinsic |
Output as:
| Claim Term |
Proposed Construction |
Support (col:ln or prosecution doc + page) |
Flag ambiguous terms with alternative constructions and outcome impact. For § 112(f) means-plus-function limitations: identify function → corresponding structure in spec → equivalents.
4. Accused Product Description
- Product name, model, purpose, high-level operation
- Feature-by-feature description paralleling claim structure
- Cite evidence precisely: document title, page/section, figure, code file:line
- Note versions/configurations analyzed
- Flag non-observable features and information gaps needing discovery
5. Element-by-Element Infringement Analysis
For each asserted claim, produce a claim chart:
| # |
Claim Limitation (as construed) |
Accused Feature (with evidence) |
Literal? |
DOE? |
Literal infringement: Apply all-elements rule. Cite specific evidence for each correspondence. Explain why each feature meets the limitation — no conclusory statements.
Doctrine of equivalents (where not literally met): Apply function-way-result or insubstantial differences test. Check DOE limitations:
| Limitation |
Test |
| Prosecution history estoppel |
Amendment-based narrowing? Festo presumption of surrender |
| Vitiation |
Would DOE eliminate the limitation? |
| Dedication to public |
Disclosed but not claimed? Johnson & Johnston |
| All-limitations rule |
Apply per-element, not to invention as a whole |
Infringement theories (as applicable):
- Direct (§ 271(a)) — single entity performs all limitations
- Inducement (§ 271(b)) — knowledge + specific intent + active inducement
- Contributory (§ 271(c)) — material component + no substantial non-infringing uses + knowledge
State per-claim infringement likelihood with qualification and basis.
6. Validity Considerations
Presumed valid (§ 282). Invalidity: clear and convincing (litigation) or preponderance (PTAB).
| Defense |
Framework |
| Anticipation (§ 102) |
Single reference with every limitation; element-by-element; check statutory bars |
| Obviousness (§ 103) |
Graham factors; secondary considerations (commercial success, long-felt need, failure of others, copying) |
| Eligibility (§ 101) |
Alice/Mayo two-step: abstract idea/natural phenomenon → inventive concept |
| § 112 defenses |
Written description, enablement, definiteness |
Flag uncited prior art not before the examiner — these are strong IPR candidates.
7. Defenses, Risks, and Strategy
Equitable defenses: Laches, equitable estoppel, implied license, exhaustion/first sale, inequitable conduct.
Damages:
| Factor |
Framework |
| Lost profits |
Panduit four-factor test |
| Reasonable royalty |
Georgia-Pacific factors; hypothetical negotiation |
| Apportionment |
Entire market value rule; isolate patented feature value |
| Marking (§ 287) |
Product marking status; pre-notice damages exposure |
| Enhanced damages |
Willfulness risk; opinion of counsel value |
Strategy: Evaluate litigation cost/timeline, design-around feasibility, licensing range from comparables, IPR timing (one-year post-complaint deadline), venue under TC Heartland, and business impact.
8. Conclusion and Recommendations
- Synthesize per-claim likelihood integrating construction + analysis + validity
- Candid strengths/weaknesses assessment
- Prioritized next steps by urgency and cost
- Information gaps requiring investigation
- Time-sensitive actions: preservation, opinion of counsel, IPR deadlines
Checks
- Maintain neutral, analytical tone — acknowledge both strengths and weaknesses
- Cite precisely: patent col:ln, prosecution doc date + page, product doc + section, cases in Bluebook
- Use
[VERIFY] for any citation not confirmed from source materials
- Distinguish known evidence from areas needing further investigation
- Qualify all assessments based on evidence strength — never overstate
- For means-plus-function claims, always identify structure + equivalents (narrower scope than general DOE)
- Flag willfulness risk early when accused infringer has knowledge of patent