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JOHN W. SCHLICHER |
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PATENTS, PATENT LITIGATION, PATENT DISPUTE RESOLUTION AND SETTLEMENT, LICENSING, ANTITRUST, LAW AND ECONOMICS |
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John W. Schlicher, Patent Law: Legal and Economic Principles, Thomson West (1992, Second Edition 2003) Prosecution History Estoppel Supreme Court Overrules the Court of Appeal’s Approach to Prosecution History Estoppel - Festo In 1992, Schlicher described how the “lower federal courts in the 1980s applied the doctrine [of file wrapper estoppel] in a rather different way” from the Supreme Court. He noted that “[t]he Supreme Court said the rule of file wrapper estoppel meant that, where a patent owner narrowed the claims in order to obtain their allowance over the prior art, the patent owner abandoned and gave up all devices that would have been within the scope of the claims prior to the amendment and were not within them after it.” He identified the Court of Appeals for the Federal Circuit’s decision in Hughes Aircraft Co. v. United States, 717 F.2d 1351 (Fed. Cir. 1983) as the point of departure. In 2000, the Court of Appeals overruled Hughes. Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558 (Fed. Cir. 2000). The Court of Appeals said that, when prosecution history estoppel exists, the effect is that “there is no range of equivalents available for the amended claim element.” After the Court of Appeals decision, Schlicher wrote an article discussing “the several respects in which the [Court of Appeal’s decision in] Festo departs from the Supreme Court’s standards” Among others, he explained that “the [Supreme] Court in Exhibit Supply did not say that an amendment to the claim precludes all application of the doctrine of equivalents to the amended element or limitation, as the Court of Appeals said in Festo.” He said, “[w]hen a patent owner asserts a claim having one scope, and abandoned that scope of rights in favor of a narrower claim, it is only that difference in scope that the Supreme Court said could not be regained through use of the doctrine of equivalents.” A short time later, the Supreme Court vacated the Court of Appeals decision. 535 U.S. 722 (2002). The Court said that prosecution history estoppel does not completely bar all application of the doctrine of equivalents to an amended element or limitation. Rather, the Court said, “[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,” citing Exhibit Supply. In his article, Schlicher explained why there might be a sensible reason to apply the doctrine of equivalence after a narrowing amendment. He said, “[t]he doctrine of equivalents is sometimes said to be designed to allow flexibility in determining the scope of rights to compensate for unavoidable difficulty in preparing claims that provided a correct scope of rights due to … the limitations of language, … or the difficulty of anticipating future changes in technology that may permit use of the invention in unexpected forms. Where the claims do not accurately define the invention for one of these reasons, someone may be able to design a device that takes advantage of the actual invention (that is, the invention described in the application), while avoiding the claims. … [E]ven if an applicant exercised the greatest possible care, an amendment may not provide a correct scope of rights due to the same types of language and technological difficulties that exist when claims are prepared initially.” The Court agreed and said that, “By amending the application, the inventor is deemed to concede that the patent does not extend as far as the original claim. It does not follow, however, that the amended claim becomes so perfect in its description that no one could devise an equivalent. After amendment, as before, language remains an imperfect fit for invention. The narrowing amendment may demonstrate what the claim is not; but it may still fail to capture precisely what the claim is. … The amendment does not show that the inventor suddenly had more foresight in the drafting of claims than an inventor whose application was granted without amendments having been submitted. It shows only that he was familiar with the broader text and with the difference between the two. As a result, there is no more reason for holding the patentee to the literal terms of an amended claim than there is for abolishing the doctrine of equivalents altogether and holding every patentee to the literal terms of the patent.” This article also described “the policies on which the Supreme Court’s decisions seem to have been based, and the policies that should control.” He noted that “The majority [in the Court of Appeals] implicitly found that the normal analysis (namely deciding literal infringement and then deciding the doctrine of equivalents) involves large costs and uncertainty, and that the resulting savings from expansive operation of prosecution history estoppel would be greater than the losses from reduced inventing incentives.” He said that as “Judge Newman pointed out how the appropriate policy decision could readily have been determined the other way, namely a decision that the benefits from increased incentives to invent under the flexible approach outweighed the costs of the uncertainty of that approach (and the subsequent uncertainty of applying the doctrine of equivalents).” He said “When there seems to be the necessity to trade off invention incentives to achieve other gains, my view is to |