En Banc Decision Minimizes Role of Dictionaries in Patent Claim Construction
In Phillips v. AWH Corp. (Fed. Cir., en banc, July 12, 2005), the principal issue presented to the Court was the extent to which it should resort to and rely on a patent’s specification in seeking to ascertain the proper scope of its claims:
This is hardly a new question. The role of the specification in claim construction has been an issue in patent law decisions in this country for nearly two centuries. We addressed the relationship between the specification and the claims at some length in our en banc opinion in Markman v. Westview Instruments, Inc., 52 F.3d 967, 979-81 (Fed. Cir. 1995) (en banc), aff’d, 517 U.S. 370 (1996). We again summarized the applicable principles in Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576 (Fed. Cir. 1996), and more recently in Innova/Pure Water, Inc. v. Safari Water Filtration Systems, Inc., 381 F.3d 1111 (Fed. Cir. 2004). What we said in those cases bears restating, for the basic principles of claim construction outlined there are still applicable, and we reaffirm them today. We have also previously considered the use of dictionaries in claim construction. What we have said in that regard requires clarification.With regard to dictionaries, the court began by noting that the methodology in Texas Digital Systems, Inc. v. Telegenix, Inc., 308 F.3d 1193 (Fed. Cir. 2002) "placed too much reliance on extrinsic sources such as dictionaries, treatises, and encyclopedias and too little on intrinsic sources, in particular the specification and prosecution history." The Texas Digital approach improperly restricts the role of the specification in claim construction because it "limits the role of the specification in claim construction to serving as a check on the dictionary meaning of a claim term if the specification requires the court to conclude that fewer than all the dictionary definitions apply, or if the specification contains a sufficiently specific alternative definition or disavowal. "
The court went on to state that the purpose underlying the Texas Digital line of cases—to avoid the danger of reading limitations from the specification into the claim—is sound. However, the distinction between using the specification to interpret the meaning of a claim and importing limitations from the specification into the claim can be a difficult one to apply in practice. Nonetheless, "the line between construing terms and importing limitations can be discerned with reasonable certainty and predictability if the court’s focus remains on understanding how a person of ordinary skill in the art would understand the claim terms."
In the end, there will still remain some cases in which it will be hard to determine whether a person of skill in the art would understand the embodiments to define the outer limits of the claim term or merely to be exemplary in nature. While that task may present difficulties in some cases, we nonetheless believe that attempting to resolve that problem in the context of the particular patent is likely to capture the scope of the actual invention more accurately than either strictly limiting the scope of the claims to the embodiments disclosed in the specification or divorcing the claim language from the specification.The court also cautioned against applying the maxim that "claims should be construed to preserve their validity" where a claim term in not ambiguous.
In Vitronics, this court grappled with the same problem and set forth guidelines for reaching the correct claim construction and not imposing improper limitations on claims. 90 F.3d at 1582. The underlying goal of our decision in Vitronics was to increase the likelihood that a court will comprehend how a person of ordinary skill in the art would understand the claim terms. See id. at 1584. In that process, we recognized that there is no magic formula or catechism for conducting claim construction. Nor is the court barred from considering any particular sources or required to analyze sources in any specific sequence, as long as those sources are not used to contradict claim meaning that is unambiguous in light of the intrinsic evidence. See id. at 1583-84; Intel Corp. v. VIA Techs., Inc., 319 F.3d 1357, 1367 (Fed. Cir. 2003). For example, a judge who encounters a claim term while reading a patent might consult a general purpose or specialized dictionary to begin to understand the meaning of the term, before reviewing the remainder of the patent to determine how the patentee has used the term. The sequence of steps used by the judge in consulting various sources is not important; what matters is for the court to attach the appropriate weight to be assigned to those sources in light of the statutes and policies that inform patent law. Vitronics, 90 F.3d at 1582. In Vitronics, we
did not attempt to provide a rigid algorithm for claim construction, but simply
attempted to explain why, in general, certain types of evidence are more
valuable than others. Today, we adhere to that approach and reaffirm the
approach to claim construction outlined in that case, in Markman and in Innova.
Instead, we have limited the maxim to cases in which “the court concludes, after applying all the available tools of claim construction, that the claim is still mbiguous.” Liebel-Flarsheim, 358 F.3d at 911; see also Generation II Orthonics Inc. v. Med. Tech. Inc., 263 F.3d 1356, 1365 (Fed. Cir. 2001) (“[C]laims can only be construed to preserve their validity where the proposed claim construction is ‘practicable,’ is based on sound claim construction principles, and does not revise or ignore the explicit language of the claims.”); Elekta Instrument S.A. v. O.U.R. Scientific Int’l, Inc., 214 F.3d 1302, 1309 (Fed. Cir. 2000) (“having concluded that the amended claim is susceptible of only one reasonable construction, we cannot construe the claim differently from its plain meaning in order to preserve its validity”); E.I. du Pont de Nemours & Co. v. Phillips Petroleum Co., 849 F.2d 1430, 1434 (Fed. Cir. 1988) (rejecting argument that limitations should be added to claims to preserve the validity of the claims). In such cases, we have looked to whether it is reasonable to infer that the PTO would not have issued an invalid patent, and that the ambiguity in the claim language should therefore be resolved in a manner that would preserve the patent’s validity.
. . .The applicability of the doctrine in a particular case therefore depends on the strength of the inference that the PTO would have recognized that one claim interpretation would render the claim invalid, and that the PTO would not have issued the patent assuming that to be the proper construction of the term.
In this case, unlike in Klein and other cases in which the doctrine of construing claims to preserve their validity has been invoked, the claim term at issue is not ambiguous. Thus, it can be construed without the need to consider whether one possible construction would render the claim invalid while the other would not. The doctrine of construing claims to preserve their validity, a doctrine of limited utility in any event, therefore has no applicability here.
Finally, the court chose not to address the issue of to what extent it is appropriate to accord any deference to any aspect of trial court claim construction rulings: "We therefore leave undisturbed our prior en banc decision in Cybor."
The critical language of claim 1 of U.S. Patent No. 4,677,798 (above) was "further means disposed inside the shell for increasing its load bearing capacity comprising internal steel baffles extending inwardly from the steel shell walls." The court concluded that this phrase imposed three clear requirements with respect to the baffles. First, the baffles must be made of steel. Second, they must be part of the load-bearing means for the wall section. Third, they must be pointed inward from the walls.
According to the couurt, the fact that the written description of the patent set forth multiple objectives to be served by the baffles recited in the claims confirms that the term “baffles” should not be read restrictively to require that the baffles in each case serve all of the recited functions.
Although deflecting projectiles is one of the advantages of the baffles of the ’798 patent, the patent does not require that the inward extending structures always be capable of performing that function. Accordingly, we conclude that a person of skill in the art would not interpret the disclosure and claims of the ’798 patent to mean that a structure extending inward from one of the wall faces is a “baffle” if it is at an acute or obtuse angle, but is not a “baffle” if it is disposed at a right angle. . . . Because we disagree with the district court’s claim construction, we reverse the summary judgment of noninfringement.
In their IP Law Bulletin for July 13, 2005, the attorneys at Foley and Lardner have already concluded that the "opinion does not represent a substantial change in the law regarding claim construction, but provides a useful and important summary of 10 years of claim construction precedent. Due to the Court’s emphasis on the specification and prosecution history, patent applicants seeking broad protection need to invest in careful patent prosecution. The effect of things said or left unsaid during preparation of the patent application and in responses to the PTO will be very difficult to change when it becomes time to enforce the resulting patent."
For more comentary on the decision, check out "Federal Circuit Orders Courts to Rely on Patent Language" by Brenda Sandburg in The Recorder on July 14, 2005.