Post-'Festo' Cases Raise More Issues

A number of recent cases have dealt with the threshold issue in a Festo analysis, namely whether an amendment to a patent claim during prosecution of the patent application narrowed the scope of the claim limitation at issue, so as to preclude reliance on the doctrine of equivalents. See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co. Ltd., 535 U.S. 722 (2002). The doctrine of equivalents allows a patent owner to extend his patent coverage to include insubstantial alterations to the invention that were not captured by the literal language of the patent claims. Applied broadly, the doctrine of equivalents impedes the ability of a competitor to design around a patented invention because he may be unsure as to what, if any, alternatives to the claim elements are covered by the patent monopoly. On the other hand, a narrow application of the doctrine aids an unscrupulous copyist, who may be able to make relatively minor changes to the invention without incurring liability for infringement. Prosecution history estoppel is the principal tool for limiting the application of the doctrine of equivalents. It excludes from the range of equivalents subject matter surrendered during prosecution of the patent application either as a result of amendments to the patent claims to overcome patentability rejections, or as a result of arguments to persuade the patent examiner to allow a claim. In a series of decisions in the Festo case, in 2000 through 2003, the U.S. Supreme Court and the U.S. Court of Appeals for the Federal Circuit rewrote the law on amendment-based prosecution history estoppel and, in so doing, severely restricted the application of the doctrine of equivalents. In Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co. Ltd., 234 F.3d 558 (Fed. Cir. 2000), the Federal Circuit, sitting en banc, adopted a bright-line rule that prosecution history estoppel would henceforth bar the application of the doctrine of equivalents to any claim limitation that was narrowed by amendment for purposes of patentability. But the Supreme Court reversed, adopting instead a new rebuttable presumption of surrender of all territory between the broader and narrower claim language when a narrowing amendment is made to satisfy any requirement of the Patent Act. A discussion of the application of the rebuttal factors is beyond the scope of this article, which concentrates solely on the threshold inquiry of whether the claim limitation at issue was narrowed. COMPARING THE TWO CLAIMS The patent owner’s first and most important line of defense against the Festo presumption is to argue that the amendment did not have the effect of narrowing the claim limitation at issue. If this argument succeeds, the presumption does not apply, and the often impossible task of rebutting the presumption of prosecution history estoppel will be avoided, thus strengthening and simplifying the patent owner’s case on infringement. The analysis of whether the claim limitation at issue was narrowed during prosecution requires a careful comparison between the scope of the claim limitation in the patent application as filed and the scope of the corresponding claim limitation in the issued patent. If the original claim language, properly construed, is broader in scope than the properly construed amended language, then the amendment was narrowed. Accordingly, the first step is to construe the original, unamended claim. Unlike the situation in which an issued claim is being construed, when construing the original claim the patent owner will urge a narrow interpretation in order to support his argument that the original claim is no broader in scope than the amended claim. Conversely, the accused infringer will urge a broad interpretation of the original claim to support his argument that the unamended claim is broader than the amended claim. This process is illustrated by a recent case. In Business Objects S.A. v. Microstrategy Inc., 393 F.3d 1366 (Fed. Cir. 2005), the Federal Circuit reversed the district court’s ruling that Business Objects was precluded from claiming infringement of claim 4 of its patent under the doctrine of equivalents, finding that the district court had erred in holding than an amendment to claim 4 during prosecution narrowed the scope of the claim. The patent at issue was directed to a method that allows end users to query a relational database without knowing a query language or understanding the structure of the relational database. The original claim language included the phrase “translating said user query into a structured query language (SQL) equivalent statement.” That language was amended to “generating queries in the predetermined query language.” The district court held that this amendment narrowed the scope of the claim limitation for purposes of patentability, raising a Festo presumption. Id. at 1375. The Federal Circuit construed the original claim wording more narrowly to mean “to translate the query specified by the lay user in terms of selected business objects into its SQL equivalent.” Rejecting the defendant’s contention that the term “SQL equivalent” referred to languages that are equivalent to SQL, the Federal Circuit looked to the way that the term was used in the patent specification to support its narrower construction. Id. The defendant contended that regardless of whether “query language” is broader than “SQL,” the qualifier “predetermined” in the new claim wording (“generating queries in the predetermined query language”) narrowed the claim limitation. The Federal Circuit disagreed, finding that by designating SQL as the language into which the business objects are to be translated, the original claim implicitly “predetermined” that the query language would be SQL. Thus, because the “predetermined” limitation was implicitly contained in the original wording, the fact that the amended wording expressly stated that the query language must be “predetermined” did not narrow the scope of the limitation. Business Objects, thus, was not barred from relying on the doctrine with respect to the amended claim limitation. Id. A similar analysis was conducted by the Federal Circuit to reach a similar result in an earlier case, TurboCare Div. of Demag Delaval Turbomachinery Corp. v. General Electric Co., 264 F.3d 1111 (Fed. Cir. 2001). The original canceled claim included the limitation of “a small clearance position” of a turbine seal with respect to the turbine shaft. A new independent claim was added that specifically defined the small clearance position with reference to contact between two surfaces. The Federal Circuit held that the small clearance position limitation was not narrowed by the amendment because the contact limitation was present in the original claim, although it was not specifically recited therein, because this was the meaning that the patent specification gave to the small clearance position. Id. at 1126. As these cases illustrate, a narrower claim construction is usually supported by referring to the patent specification to define the meaning of the claim terms, and there is certainly ample authority for construing disputed claim terms in the context of the patent specification. See, e.g., United States v. Adams, 383 U.S. 39, 49 (1966). But the party who is urging a broader claim construction often relies instead on dictionaries to support its broader definitions of claim terms. In recent years, in order to facilitate de novo review of literal claim construction and increase the predictability of the outcome, an issue on which there is usually conflicting expert testimony, the Federal Circuit has sometimes elevated dictionary definitions above the patent specification as the primary source of meaning for claim terms. See, e.g., Texas Digital Systems Inc. v. Telegenix Inc., 308 F.3d 1193 (Fed. Cir. 2002), cert. denied 538 U.S. 1058 (2003). The Federal Circuit, sitting en banc, is currently tackling the issue of what role dictionaries and other similar sources should play in claim construction. See Phillips v. AWH Corp., 376 F.3d 1382 (Fed. Cir. 2004). The decision in Phillips, expected later this year, will affect how the analysis of the scope of original and amended claims is conducted for the purpose of determining whether there has been a narrowing amendment. REWRITING DEPENDENT CLAIMS The issue of whether there is a narrowing amendment when a dependent claim is rewritten in independent form has been addressed in several post- Festo decisions by the Federal Circuit. A dependent claim is one that includes by reference all the limitations of an independent claim, and generally either limits an element which is recited in the independent claim or adds a further element. The Patent Office encourages the use of dependent claims for ease of examination by charging significantly higher fees for the filing of multiple independent claims. It is a common practice in patent prosecution to rewrite a dependent claim in independent form, accompanied by the cancellation of the original independent claim, in response to a rejection of the independent claim for patentability reasons. The mere rewriting of a dependent claim in independent form does not change the scope of the claim because 35 U. S. C. 112, � 4 provides that a claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers. However, in Deering Precision Instruments LLC v. Vector Distribution Systems Inc., 347 F.3d 1314 (Fed. Cir. 2003), cert. denied 124 S. Ct. 1426 (2004); Ranbaxy Pharmaceuticals Inc. v. Apotex Inc., 350 F.3d 1235 (Fed. Cir. 2003); and, most recently, in Honeywell Int’l Inc. v. Hamilton Sunstrand Corp., 370 F.3d 1131 (Fed. Cir. 2004) (en banc), the Federal Circuit held that the rewriting of a dependent claim in independent form, accompanied by cancellation of the broader claim from which the rewritten claim depended, constitutes a narrowing amendment invoking a Festo estoppel. Both Deering and Ranbaxy involved dependent claims that circumscribed a limitation found in the independent claims. In Honeywell, the Federal Circuit extended its Deering and Ranbaxy holdings to a situation in which the dependent claim did not circumscribe an element already included in an independent claim, but, rather, added a new element. In Deering and Ranbaxy, the presumption of surrender of all territory between the broader and narrower claim language was readily measured by the difference between the scope of the pertinent limitation in the canceled independent claim and that of the corresponding limitation in the rewritten dependent claim. The measurement of the territory which was surrendered in Honeywell is more problematic. In Honeywell, the Festo presumption of surrender was held to apply to all equivalents for the additional limitation found in the dependent claim, even though that limitation had never been narrowed since it was not included in the canceled independent claim. As Judge Pauline Newman pointed out in her dissenting opinion, the logical problem in applying the Festo presumption of surrender to a rewritten dependent claim that added a new element, rather than circumscribed a limitation already contained in the canceled independent claim, is that one of the Festo markers for measuring the territory surrendered by the amendment is missing, namely the prior broader claiming of the limitation at issue. See id. at 1152. The majority in Honeywell, while acknowledging that the scope of the rewritten claim remained unchanged, focused on the fact that something was surrendered to secure the patent when the original independent claim was canceled, and apparently felt that any instance of surrender of claim coverage must give rise to a Festo estoppel. See id. at 1142. Accordingly, it is far from clear that the Honeywell presumption of surrender of all equivalents for any additional element contained in a dependent claim rewritten in independent form, accompanied by cancellation of the original independent claim, can be avoided by the simple, albeit costly, expedient of filing all claims in independent form. In future cases the Federal Circuit could easily extend its rationale in Honeywell to measure all independent claims in the issued patent against any canceled independent claim, and to bar all equivalents for additional elements found in the issued independent claims, but not found in the canceled claim, notwithstanding the fact that such additional elements were never narrowed by amendment. Honeywell’s petition for a writ of certiorari is pending, and the Supreme Court has invited the solicitor general to file a brief expressing the views of the United States. Honeywell Int’l Inc. v. Hamilton Sunstrand Corp., 125 S. Ct. 458 (2004). As the Federal Circuit noted in Honeywell, the amicus brief filed by the United States in Festo urged the high court to adopt the position that rewriting a dependent claim in independent form cannot give rise to an estoppel. It is to be expected that the government will take the same position in Honeywell. Catriona M. Collins is a senior attorney and intellectual property litigator at New York’s Cowan, Liebowitz & Latman. She can be reached at [email protected]. The author represented the plaintiff in the TurboCare case discussed in this article.