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“A” or “an” Meant “One or More” in an Open-Ended Claim Containing “Comprising,” and Intrinsic Evidence Did Not Support the District Court’s Importation of a Temporal Limitation into a Claim

07-1262
January 15, 2008

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Last Month at the Federal Circuit - February 2008

Judges: Michel, Rader (author), Moore

[Appealed from: N.D. Ill., Judge Moran]

In Baldwin Graphic Systems, Inc. v. Siebert, Inc., No. 07-1262 (Fed. Cir. Jan. 15, 2008), the Federal Circuit determined that the district court correctly construed one of the claim terms of Baldwin Graphic Systems, Inc.’s (“Baldwin”) U.S. Patent No. Re. 35,976 (“the Reissue patent”), erred in construing another term, and affirmed its grant of SJ of noninfringement with respect to that patent. However, the Court found that the district court erred in its construction of Baldwin’s U.S. Patent No. 5,974,976 (“the ’976 patent”) and, thus, reversed the district court’s grant of SJ of noninfringement with respect to that patent and remanded.

Baldwin’s patents claim a system for cleaning a cylinder of a printing press using strips of cleaning fabric, and methods for making those systems. Baldwin sued Siebert, Inc. (“Siebert”), asserting that Siebert’s packaged fabric rolls infringed claim 32 of the Reissue patent, and independent claims 1 and 14 and certain dependent claims of the ’976 patent.

Claim 32 of the Reissue patent recites, inter alia, “[a] pre-packaged, pre-soaked cleaning system . . . comprising . . . a pre-soaked-fabric roll . . . having a sealed sleeve.” The district court construed “a pre-soaked fabric roll” to mean “a single pre-soaked fabric roll” and “sealed sleeve” to mean “heat-sealed sleeve.” Based on these constructions, the district court granted SJ of noninfringement to Siebert with respect to the Reissue patent. Similarly, the district court construed the claims of the ’976 patent and granted SJ of noninfringement to Siebert with respect to that patent as well. Specifically, claim 1 of the ’976 patent recites, inter alia, “reduced air content cleaning fabric,” and claim 14 recites, inter alia, “reducing air content of a strip of cleaning fabric.” Addressing these terms together, the district court initially concluded that “reduced air content cleaning fabric” was not limited to a particular method for producing reduced air content cleaning fabric. However, on reconsideration, the district court construed “reduced air content cleaning fabric” to mean “a fabric whose air content has been reduced by some method prior to being wound on a roll” and as a result, granted SJ of noninfringement to Siebert. Baldwin appealed.

On appeal, the Federal Circuit first addressed the district court’s grant of SJ with respect to the Reissue patent. The Court determined that the district court erred in construing “a pre-soaked fabric roll” as being limited to a single roll. It noted that it has repeatedly emphasized that an indefinite article “a” or “an” in patent parlance carries the meaning of “one or more” in open-ended claims containing the transitional phrase “comprising.” Slip op. at 7. It explained that “‘a’ or ‘an’ can mean ‘one or more’ is best described as a rule, rather than merely as a presumption or even a convention.” Id. The Court noted that the exceptions to this rule are extremely limited and that a patentee must evince a clear intent to limit “a” or “an” to “one.” It observed that the subsequent use of definite articles “the” or “said” in a claim to refer back to the same claim term does not change the general plural rule, but simply reinvokes that nonsingular meaning.

Applying these principles, the Federal Circuit noted that nothing in the claim language, specification, or prosecution history compelled an exceptional reading of “a” in this case. It reasoned that the district court erred by misapplying the term “said fabric roll” in the claim to arrive at its construction. It noted that the use of “said” or “the” to refer back to an initial indefinite article did not imply the singular and that because the initial indefinite article “a” carries either a singular or plural meaning, any later reference to that same claim element merely reflects the same potential plurality. In addition, contrary to the district court’s analysis, the Federal Circuit held that M.P.E.P. § 2173.05(e), which describes the need for claim terms to have proper antecedent bases, was inapposite here because the confusion or indefiniteness problem addressed by § 2173.05(e) did not arise in this claim. Accordingly, the Federal Circuit found that “a pre-soaked fabric roll” was not limited to a single roll.

The Federal Circuit, however, agreed with the district court’s construction of “sealed sleeve” as being limited to “heat-sealed sleeve.” It explained that it has consistently recognized that the Patent Act prevents an applicant from adding new subject matter during prosecution. In this case, during the prosecution of the Reissue patent, the examiner refused to allow the applicants to amend the specification to remove references to “heat” as the way of sealing the sleeve because this change would have broadened the patent and introduced impermissible new matter not included in the initial disclosure. In light of these facts, the Court concluded that the district court correctly construed “sealed sleeve,” rendering Siebert’s fabric rolls noninfringing, and thus affirmed the district court’s grant of SJ of noninfringement with respect to the Reissue patent.

The Federal Circuit then turned to the district court’s grant of SJ of noninfringement with respect to the ’976 patent. It determined that the district court erred by limiting the claimed phrase “reduced air content cleaning fabric” to “a fabric whose air content has been reduced by some method prior to being wound on a roll.” The Court explained that although the parties agreed that the terms “reduced air content cleaning fabric” in claim 1 and “reducing air content of a strip of cleaning fabric” in claim 14 were substantially similar, the district court erred in construing them together. Doing so, noted the Court, blurred an important difference between the two independent claims, namely, that claim 1 is an apparatus claim and claim 14 is a method claim. It noted that courts must generally take care to avoid reading process limitations into an apparatus claim because the process by which a product is made is irrelevant to the question of whether that product infringes a pure apparatus claim.

The Court observed that claim 1 and its dependent claims did not have any process limitations and that, therefore, they were not limited to any particular process or method of making the claimed system or to any particular sequence of air content reduction relative to winding. And unlike claim 1, noted the Court, claim 14 and its dependent claims were method claims and recited a series of steps and specified the limits on the performance of those steps. It added that courts must carefully avoid importing limitations from the specification into method claims and that although a method claim necessarily recites the steps of the method in a particular order, as a general rule, the claim is not limited to performance of the steps in the order recited unless the claim explicitly or implicitly requires a specific order.

The Court reasoned that in this case, the claims themselves contained no basis to require air content reduction before winding. It noted that though the claims, specification, and prosecution history required that the air content of the cleaning fabric be reduced before saturation, this did not mean that the air content must be reduced prior to winding on the roll. It found that in relying on the dependent claims to inform the meaning of “reduced air content cleaning fabric,” the district court effectively imported limitations from dependent claims into the independent claims, contrary to basic claim construction principles. The Court added that the dependent claims simply did not support the district court’s determination that the fabric in all instances must have its air content reduced before being wound on a roll.

In addition, the Court reasoned that neither the specification nor the prosecution history supported the district court’s construction. It explained that the language in the specification relied upon by the district court did not support the temporal constraint imposed by the district court. In addition, noted the Court, the district court’s reliance on the prosecution history—namely, the singular comment by the applicants during prosecution that the air content reduction occurs before saturation—provided no support whatsoever for the district court’s construction requiring air content reduction before winding. “By no means [did] this statement constitute something akin to a disavowel of claim scope,” stated the Court. Id. at 14. Accordingly, the Federal Circuit held that the district court’s final construction of “reduced air content cleaning fabric” was erroneous and that the district court’s initial construction of this term as not limited to a particular method for producing reduced air content cleaning fabric was correct. In light of this conclusion, the Federal Circuit reversed the district court’s grant of SJ of noninfringement with respect to the ’976 patent and remanded.