Understanding Infringement Analysis in Patent Law

1. Chapter 8 Infringement

2. Statutory Provision: 271 • Basic statute provides: • “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.” • The statute itself does not specify how infringement analysis is to occur. Courts have developed a common law concerning the relationship between the patent document (particularly the claims) and infringement analysis.

3. History • 1790-1836: No claims required in the patent document. Infringement analysis proceeded by having a jury compare the accused device to what was described in the whole patent specification to determine whether the two were “substantially the same.” • 1836: Claims required. • 1854: Winans v. Denmead: The Court narrowly rejects the view that claims provide the exclusive definition of the invention. • 1877: Merrill v. Yeomans: The Court seems to embrace the dissenting view from Winans, but the Winans view lives on as “the doctrine of equivalents.”

4. History • 1898: Supreme Court invokes the “reverse doctrine of equivalents” to hold that even where an accused device is covered literally by claim language, still the accused device might avoid infringement. • Early 20th Century: Infringement analysis is highly similar to today’s analysis. • 1996: Markman v. Westview Instruments: Supreme Court holds claim interpretation to be an issue of law. • 1997: Warner-Jenkinson: S.Ct. reaffirms the doctrine of equivalents. • 2002: Festo: S.Ct. stops the Federal Circuit from limiting the doctrine of equivalents with an expanded doctrine of prosecution history estoppel.

5. Structure of Infringement Analysis Defendant’s “accused product” (or process): Real World Thing Plaintiff’s Patent (specifically the claims): Legal Document vs.

6. Infringement Analysis – Option I • Literal Infringement • Claim Language Provides Starting Point. • Other Parts of Patent Document Used Too. • Specification. • Drawings. • Prosecution History (or “File Wrapper”). • Reverse Doctrine of Equivalents. • Narrow Exception. • Even if the claims do literally cover the accused product, the defendant may escape infringement if the defendant “has so far changed the principle of the device that the claims of the patent, literally construed, have ceased to represent [the] actual invention.”

7. Infringement Analysis – Option II • Infringement Via the Doctrine of Equivalents (DOE). • Claim language still provides the starting point. • Must identify element(s) not literally found in accused product or process. • Must identify some structure in the accused product or process that is “equivalent” to the missing element(s). • Every element or an equivalent MUST be present in the accused device or process. • Major Limitations on DOE: • Prosecution History Estoppel – Cannot recapture through equivalents analysis what has been “surrendered” at the PTO. • Every element rule (as mentioned above). • Prior Art – If patentee’s “equivalent” analysis would mean that the claim + equivalents would cover prior art, then the equivalents analysis must be rejected. This is a corollary to the principle that patents can never detract from the prior art.

8. Infringement Analysis – Process Issues • Literal Infringement • Claim is interpreted as a matter of law. • Application of claim to accused device is a question of fact for the jury. • DOE • DOE is applied as a question of fact for the jury (this is consistent with the doctrine’s history). • Limitations on DOE, particularly prosecution history estoppel, are issues of law for the court. Note: Diminishing the scope of equivalents analysis shifts power from the jury to the courts.

9. Merrill v. Yeomans • Plaintiff’s patent included the following claim: • “I claim the above-described new manufacture of the deodorized heavy hydrocarbon oils, suitable for lubricating and other purposes, free from the characteristic odors of hydrocarbon oils, and having a slight smell like fatty oil, from hydrocarbon oils, by treating them substantially as is hereinbefore described.” • Court is confronted with two issues: • 1. How should this claim be interpreted? (Does it cover a product or a process?) • 2. Should the patentee receive any “liberal construction” to cover the accused products?

10. Merrill v. Yeomans • The Court resolves the two issues in this way: • 1. The claim covers a process. Note that the Court begins with the language of the claim; it also considers standard definitions of the relevant words in the claim (“The word “manufacture” in this sentence is one which is used with equal propriety to express the process of making an article, or the article so made.”); finally, it looks for clues in the rest of the patent specification. • 2. On the second issue, the Court notes the development of patent law and concludes: “The developed and improved condition of the patent law, and of the principles which govern the exclusive rights conferred by it, leave no excuse for ambiguous language or vague descriptions.”

11. Markman • The claim at issue: • 1. The inventory control and reporting system, comprising: • a data input device for manual operation by an attendant, the input device having switch means operable to encode information relating to sequential transactions, each of the transactions having articles associated therewith, said information including transaction identity and descriptions of each of said articles associated with the transactions; • a data processor including memory operable to record said information and means to maintain an inventory total, said data processor having means to associate sequential transactions with unique sequential indicia and to generate at least one report of said total and said transactions, the unique sequential indicia and the descriptions of articles in the sequential transactions being reconcilable against one another; • a dot matrix printer operable under control of the data processor to generate a written record of the indicia associated with sequential transactions, the written record including optically-detectable bar codes having a series of contrasting spaced bands, the bar codes being printed only in coincidence with each said transaction and at least part of the written record bearing a portion to be attached to said articles; and, • at least one optical scanner connected to the data processor and operable to detect said bar codes on all articles passing a predetermined station, • whereby said system can detect and localize spurious additions to inventory as well as spurious deletions therefrom.

12. Markman • The Court’s simplification: • The Markman system consists of a keyboard [marked 32 in Figure 8-1] and data processor [30] to generate written records [40] for each transaction, including a bar code [80] readable by optical detectors [70] operated by employees, who log the progress of clothing through the dry-cleaning process. • The district court decided that, as a matter of law, the term “inventory” in Markman’s patent encompasses “both cash inventory and the actual physical inventory of articles of clothing.”

13. Markman • Examples from the specification in which the term "inventory" seems clearly to encompass information about "articles of clothing“: • This invention relates to inventory control devices capable of monitoring and reporting upon the status, location and throughput of inventory in an establishment. [Col. 1, lines 12-17.] • The best inventory control and management reporting information systems has [sic] the ability to determine and report the current location of any given article in inventory. [Col. 5, lines 14-17.] • Every transaction is recorded, including identification of the articles placed in inventory. [Col. 5, lines 8-10.] • Incoming articles to be placed in inventory are accumulated over a counter . . . . [Col. 6, lines 7-8.] • Articles to be cleaned are associated with a unique bar code indicia for later automatic or semiautomatic optical scanning and data input, whereby the progress of articles through the laundry and drycleaning systems can be completely monitored. [Col. 2, lines 53-57.] • Note: Markman conceded that the term “article” in the specification refers to “articles of clothing.”

14. Winans • The claim at issue: • “What I claim as my invention, and desire to secure by letters-patent, is making the body of a car for the transportation of coal, &c., in the form of a frustum of a cone, substantially as herein described, whereby the force exerted by the weight of the load presses equally in all directions, and does not tend to change the form thereof, so that every part resists its equal proportion, and by which, also, the lower part is so reduced as to pass down within the truck frame and between the axles, to lower the centre of gravity of the load without diminishing the capacity of the car as described.”

15. Winans • The problem is that the defendant’s product is not in the form of a perfect cone (which has a circular cross-section). Instead it is in the form of a multi-sided shape. • The Court allows a variation from the language of the claim, holding that the defendant’s device would infringe if it is “so near to a true circle as substantially to embody the patentee’s mode of operation, and thereby attain the same kind of result as was reached by his invention.” • Why? “Patentees sometimes add to their claims an express declaration, to the effect that the claim extends to the thing patented, however its form or proportions may be varied. But this is unnecessary. The law so interprets the claim without the addition of these words.”

16. Warner-Jenkinson • 1. The Court reaffirms the vitality of the doctrine of equivalents, but … • 2. It also is concerned that the doctrine of equivalents has been too liberally applied. • The Court limits DOE in two ways: • (i) It places the burden of disproving prosecution history estoppel on the plaintiff. • (ii) It also requires DOE analysis to proceed on an element-by-element basis. It describes the “essential inquiry: Does the accused product or process contain elements identical or equivalent to each claimed element of the patented invention?” • The Court also rejects imposing any intent requirement. Evidence of “copying” is unnecessary. Indeed, “intent plays no role in the application of the doctrine of equivalents.”

17. Festo • Reaffirms the vitality of DOE (again). • Refines the burden on patentee: • Presumption: “A patentee’s decision to narrow his claims through amendment may be presumed to be a general disclaimer of the territory between the original claim and the amended claim.” But … • Overcoming the presumption: “[T]he patentee still might rebut the presumption that estoppel bars a claim of equivalence. The patentee must show that at the time of the amendment one skilled in the art could not reasonably be expected to have drafted a claim that would have literally encompassed the alleged equivalent.”

18. Festo • Relationship between literal infringement and DOE: • Consider the “magnetizable” sleeve in Festo’s claims. The parties agreed for purposes of this litigation that SMC’s sleeve was not magnetizable. But that was probably a mistake by the plaintiff’s attorneys. • SMC’s sleeve was made not of pure aluminum, but of an “aluminum alloy” having sufficient magnetic properties to “form[] a magnetic circuit in substantially the same way as the sleeve of the patent” and thereby to “serve the function of reducing magnetic leakage.” • The Festo Corp. could have argued that SMC’s alloy was “magnetizable” within the meaning of Festo’s patent. A standard dictionary definition of “magnetizable” is “capable of being magnetized” and, in turn, “magnetize” can mean either “to attract like a magnet” or “to communicate magnetic properties to.”

19. Reverse DOE • Very rare: The issue can only arise where the PTO has granted a very broad patent (rare) and the accused infringer has made some great leap beyond the patented technology. • Scripps Clinic case might be a good example where the doctrine could have been used. • The claim, as it so happens, was very broad because it literally encompassed both purified human clotting factor and ultra-pure, genetically engineered human clotting factor. • The breadth of the claim was probably not apparent when it was granted. • Note that the difference in the technology used to produce the purified clotting factor has immense significance. One can transmit AIDs; the other can’t.

20. Bolar: Experimental Use (Non)Exception • The court holds the “experimental use” exception to be “truly narrow.” It has no application if the “inquiry has definite, cognizable, and not insubstantial commercial purposes.” • In other words, the exception has no practical application. • In other countries, the law is different. • If your client wants an experimental use exception, the solution is to conduct the research in … Canada (or the UK, Germany, Japan, etc.). Note that the results of the research can be patented here in the U.S.