Infringement & the Doctrine of Equivalents I

Infringement & the Doctrine of Equivalents I Class Notes: February 27, 2003 Law 677 | Patent Law | Spring 2003 Professor Wagner

Today’s Agenda • Basics of Infringement • The Doctrine of Equivalents Law 677 | Spring 2003

The Basics of Infringement • The patent right: the right to exclude others from . . . • Making • Using • Selling • Offering to sell • Importing • Categories of Infringement • Direct Infringement • Indirect Infringement [March 20] Law 677 | Spring 2003

The Basics of Infringement (2) • Forms of Direct Infringement • Literal infringement • Infringement via the Doctrine of Equivalents Literal Infringement => consider this claim . . . • A writing implement comprising: A wooden cylinder with a hollow core A cylinder of graphite in said hollow core A small cylinder of eraser material attached to one end of the wooden cylinder Which of the following infringes the claim: • A wooden pencil with a small metal clip for shirt-pocket storage • A plastic pencil (body made of plastic) • A pencil without an eraser Law 677 | Spring 2003

The Doctrine of Equivalents • Winans v Denmead (1853) • What was significant about the Winans invention? • Why did the Court find infringement by Denmead? Law 677 | Spring 2003

The Doctrine of Equivalents • Graver Tank v Linde (1950) • Technology: welding fluxes • Invention: alkaline earth metal + calcium fluoride • Accused: non-alkaline earth metal + calcium fluoride • Why are these facts relevant to infringement? • Alkaline and non-alkaline metals performed similarly • The prior art suggested that even non-alkaline metals would work • No evidence of independent testing by Linde Law 677 | Spring 2003

The Doctrine of Equivalents • The Influence of Graver Tank - establishes modern DOE • The test for DOE: when the accused device performs “substantially the same function in substantially the same way to achieve substantially the same result” (“Function-Way-Result test”) • “What determines equivalency must be determined against the context of the patent, the prior art, and the particular circumstances of the case” • “Equivalence, in the patent law, is not the prisoner of a formula and is not an absolute to be considered in a vacuum.” • “An important factor is whether persons reasonably skilled in the art would have known of the interchangeability of an ingredient not contained in the patent with one that was.” • A finding of equivalence is a determination of fact • “The record contains no evidence that [the accused device] was developed as the result of independent research experiments.” Law 677 | Spring 2003

The Doctrine of Equivalents • Graver Tank, continued. • How does the majority describe the purpose/use of the DOE? • Would a patent without DOE be a “hollow and useless thing”? • What is the dissent’s primary objection? • Why does the dissent note the possibility of ‘reissue’? • Are you convinced? Law 677 | Spring 2003

The Doctrine of Equivalents • Warner-Jenkinson v Hilton Davis (1997) • Key limitation: “a pH of approximately 6.0 to 9.0” • Accused process: pH of 5.0 • Question 1: Does the DOE survive the 1952 Act? • Question 2: What are the boundaries of the DOE? • The court “establishes” the “all-elements-rule”: the DOE is to be applied on an element-by-element basis. (Note that this had been the law of the Federal Circuit since 1987.) • Does the ‘all elements rule’ reconcile the tension between the DOE and the notice function of claims? Law 677 | Spring 2003

The Doctrine of Equivalents • Warner-Jenkinson v Hilton Davis (1997) • The court declines to determine the appropriate ‘linguistic framework’ for the DOE • The DOE remains a question of fact, but see ‘famous footnote 8’ (p. 898) • Whether the DOE applies is unrelated to the mental state of the infringer (Why?) • Prosecution history estoppel (PHE) survives, with a new ‘presumption’. (Why?) • The DOE may apply to any technology, whether known or unknown at the time of filing. (Why is this important?) Law 677 | Spring 2003

The Doctrine of Equivalents • What is the ‘best’ argument or explanation for the DOE? • Equity/Fairness: An inventor’s rights would be valueless without DOE. • Furtherance of the Law’s Purpose: Allowing ‘equivalent’ copies of patented inventions undermines the entire system. • (Broad) Claim Construction: we presume patentees have patented all they are entitled to. Does any of these justify the costs of the DOE? Law 677 | Spring 2003

Next Class • Infringement & the Doctrine of Equivalents II • The All Elements Rule • Means-Plus-Function Claims Law 677 | Spring 2003

Infringement & the Doctrine of Equivalents I