Direct Infringement

Direct patent infringement is the most fundamental form of patent infringement: STATUTORY TEXT: 35 U.S.C. § 271(a): 'Except as otherwise provided in this title, whoever without authority makes, uses, offers to sell, or sells any patented invention, within the United States or imports into the United States any patented invention during the term of the patent therefor, infringes the patent'; STRICT LIABILITY: direct infringement is a strict liability offense; the infringer need not know the patent exists; the infringer need not intend to infringe; good faith is not a defense to liability (though it may affect willfulness and damages); INFRINGING ACTS: (a) MAKES: manufacturing or fabricating the patented invention; (b) USES: using the patented invention; using a patented method; (c) OFFERS TO SELL: offering for sale in the US even if actual sale occurs outside the US; 3D Medical Imaging v. Varian (Fed. Cir. 2015): offer to sell does not require consummation of the sale; (d) SELLS: selling the patented invention in the US; (e) IMPORTS: importing the patented invention into the US; important for global supply chains; WITHIN THE UNITED STATES: each act must occur 'within the United States'; infringement does not occur if the act occurs entirely outside the US; extraterritorial activity may be relevant to indirect infringement; exception: patented process — if even one step occurs in the US, the entire process may infringe; DURING THE PATENT TERM: infringement only during the 20-year patent term; no damages before patent issuance; for method claims, each use during the patent term can be a separate infringement.

Proving direct infringement requires satisfying the all-elements rule: ALL-ELEMENTS RULE: to prove literal direct infringement, the patent owner must prove that EVERY element of at least one patent claim is present in the accused product or process; if any single element is missing, there is no literal infringement; TWO-STEP ANALYSIS: Step 1: CLAIM CONSTRUCTION — determine the meaning and scope of each claim limitation; construed by the court (judge question — Markman hearing); de novo review on appeal; Step 2: COMPARISON — compare each construed claim element to the accused product; this is a factual comparison; jury question; reviewed for substantial evidence; LITERAL INFRINGEMENT: each claim element is present in the accused product, exactly as construed; DOCTRINE OF EQUIVALENTS (DOE): even without literal infringement, infringement may be found if the accused element performs substantially the same function in substantially the same way to achieve substantially the same result (function-way-result test; or insubstantial differences test); PROSECUTION HISTORY ESTOPPEL: limits DOE; if the patent owner narrowed a claim to obtain the patent, the patent owner cannot use DOE to recapture surrendered territory; Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co. (S.Ct. 2002): narrowing amendment creates rebuttable presumption of estoppel for the entire surrendered range; INDEPENDENT CLAIMS vs. DEPENDENT CLAIMS: proving infringement of an independent claim does not automatically prove infringement of dependent claims; dependent claims add additional limitations that must each be present; MEANS-PLUS-FUNCTION CLAIMS (§ 112(f)): claim elements in 'means for' form are construed to cover the corresponding structure in the specification and its equivalents; DOE applies differently.

Claim construction is the single most important step in any infringement analysis: MARKMAN HEARING: the Supreme Court in Markman v. Westview Instruments (S.Ct. 1996) held that claim construction is a matter of law for the judge, not the jury; district courts typically hold a Markman hearing (claim construction hearing) where parties argue the meaning of disputed claim terms; INTRINSIC EVIDENCE (primary): claim language itself (how is the term used in the claims?); specification (how does the patent describe the term?); prosecution history (what did the patent owner say to the USPTO during examination?); EXTRINSIC EVIDENCE (secondary): dictionaries; technical treatises; expert testimony on POSITA understanding; Phillips v. AWH Corp. (Fed. Cir. 2005 en banc): intrinsic evidence takes priority over extrinsic; claims should be construed in light of the specification but not limited to the specific embodiments in the specification; CLAIM DIFFERENTIATION DOCTRINE: if two claims use different language, those differences should generally be given different scope; a dependent claim's additional limitation is presumptively not in the independent claim; PREAMBLE: preamble is usually NOT limiting (it describes the environment); but if the preamble is essential to understand the claim body, it may be limiting; COMPRISING vs. CONSISTING OF: 'comprising' = open-ended (additional elements OK); 'consisting of' = closed (only listed elements); 'consisting essentially of' = closed except for elements that don't materially affect the basic and novel characteristics; EFFECT ON INFRINGEMENT SCOPE: narrow claim construction → fewer products infringe; broad claim construction → more products infringe + more validity risk; the accused infringer argues for narrower construction; the patent owner argues for broader.

Defendants in direct infringement cases can assert several categories of defenses: NON-INFRINGEMENT DEFENSES: (a) LITERAL NON-INFRINGEMENT: the accused product is missing at least one claim element; claim construction arguments; structural/functional differences from the claimed invention; (b) NO DOCTRINE OF EQUIVALENTS: insubstantial differences test not met; prosecution history estoppel bars DOE (narrowing amendment); prior art bars DOE (the accused equivalent would have been obvious over prior art); dedication to public — if the specification disclosed but did not claim the accused element, it is dedicated to the public (Johnson & Johnston Assocs. v. R.E. Service Co., Fed. Cir. 2002); VALIDITY DEFENSES (§ 282): patent invalidity is a defense to infringement; must prove invalidity by clear and convincing evidence; defenses include: prior art (§ 102 anticipation; § 103 obviousness); § 112 written description, enablement, definiteness; double patenting; misuse; UNENFORCEABILITY DEFENSES: inequitable conduct: intentional withholding of material prior art from USPTO; patent misuse: use of patent rights beyond their proper scope (violated antitrust; mandatory package licensing; tie-ins); LICENSE DEFENSE: accused infringer has a license (express; implied; through exhaustion); licensed products exhaust the patent rights; EXHAUSTION (IMPRESSION PRODUCTS): once a patent holder sells a patented item, the patent rights are exhausted as to that item; authorized sale in the US exhausts US patent rights; authorized sale outside the US also exhausts US rights (Impression Products v. Lexmark, S.Ct. 2017); STATUTE OF LIMITATIONS: § 286: no recovery for infringement before 6 years prior to complaint filing; LACHES: SCA Hygiene (S.Ct. 2017) largely eliminated laches as a defense for patent damages (§ 286 statute of limitations governs).

Method claim infringement has unique considerations, especially for claims performed by multiple parties: METHOD CLAIM INFRINGEMENT: to infringe a method claim, every step of the method must be performed; performance of all steps = direct infringement; partial performance = no direct infringement; SINGLE-ACTOR REQUIREMENT: for direct infringement of a method claim, all steps must be performed by a single entity; this created the 'divided infringement' problem; DIVIDED INFRINGEMENT PROBLEM: many modern methods (especially internet and software methods) involve steps performed by different parties; example: steps A and B by the user; step C by the service provider; if all steps are not performed by ONE person, there is no single-actor direct infringement; AKAMAI TECHNOLOGIES V. LIMELIGHT NETWORKS (Fed. Cir. 2015 en banc): to establish direct infringement when steps are performed by multiple parties, all steps must be attributable to a single entity: (1) that entity directs or controls the other parties' performance; OR (2) the parties form a joint enterprise; DIRECTION AND CONTROL: a party 'directs or controls' another if it conditions participation in an activity on performance of a step; sets the manner or timing of performance; SINGLE ACTOR SCENARIOS: the defendant itself performs all steps; the defendant directs others to perform the remaining steps; INDUCED INFRINGEMENT ALTERNATIVE: when divided infringement prevents direct infringement liability, the patent owner may pursue induced infringement under § 271(b) if: a single actor induced third parties to collectively perform all steps; and that actor had knowledge of the patent and intended infringement; PROCESS CLAIMS AND IMPORTS: 35 U.S.C. § 271(g): importing a product made by a patented process infringes the process patent; prevents circumvention by manufacturing abroad.