Two recent claim construction decisions by separate panels of the U.S. Court of Appeals for the Federal Circuit suggest that non-asserted or cancelled claims should be examined to determine if the preferred embodiment is found there and, if it is, asserted claims need not be construed to include preferred embodiments. PSN Illinois, LLC v. Ivoclar Vivadent, Inc., No. 07-1512 (Fed. Cir., May 6, 2008) (Michel, J.) and Helmsderfer v. Bobrick Washroom Equipment, Inc., Case No. 08-1027 (Fed. Cir., June 4, 2008) (Moore, J.).
In PSN, the Federal Circuit panel unanimously concluded that the district court construed a claim term too narrowly, but affirmed the finding of non-infringement nonetheless. PSN alleged that Ivoclar infringed its patent directed to a method of fabricating porcelain veneers for teeth using an investment casting process. The asserted claim recited a limitation regarding the veneer being "ready for mounting" following the removal of a model of a patient's tooth made from an impression of the patient's mouth that the veneer was formed upon. The district court construed "ready for mounting" as "leaving the veneer restoration ready to be fitted to and cemented on a patient's tooth for which it was custom-made." The district court determined that Ivoclar did not infringe, as the Ivoclar veneer required substantial work after it was removed from the investment material that the veneer is formed upon. PSN appealed.
The PSN panel commenced its analysis by agreeing with PSN that the district court construed "ready for mounting" too narrowly by excluding finishing activities. The Court noted that the claim language did not provide guidance to the meaning of "ready for mounting" and that the specification did not specifically define the term. However, the Federal Circuit noted that the specification did teach in the summary of invention that some finishing steps may be performed after the veneer is removed from the investment material. The district court had focused on a preferred embodiment that described finishing steps occurring prior to removing the veneer from the investment material. The Court determined that the term should be construed in a manner that includes both the description in the summary of the invention, as well as the specific embodiment. Thus, "ready for mounting" should be construed to allow some finishing after removing the veneer from the investment material.
The Court noted that claims do not need to be construed in a manner so that all claims cover all embodiments, but a court needs to be mindful that "disclosed embodiments may be within the scope of other allowed but unasserted claims." The Court further pointed out that, during prosecution, an applicant may have canceled pending claims, but not amended the specification to delete disclosure relevant only to the canceled claims. In such circumstances, a disclosed embodiment may not be within the scope of the asserted claims. The Federal Circuit then applied the properly constructed claim term to the accused process and determined that Ivoclar's process involved more than mere finishing after removing the investment material and is not ready for mounting. Consequently, it did not infringe PSN's asserted claim.
In the second decision, Helmsderfer, a different panel unanimously affirmed the claim construction in a patent infringement action. Helmsderfer alleged that Bobrick Washroom Equipment infringed two claims of its patent directed to a baby diaper-changing station for use in a public restroom. The asserted claims depended from an independent claim that recited, in part, "the platform top surface is partially hidden from view." At a Markman hearing the district court construed "partially hidden from view" to mean "hidden from view to some extent, but not totally hidden from view." Helmsderfer appealed, arguing that the term should have been construed to mean "at least some of the top surface is blocked from being seen," a construction that would include a top surface that is completely hidden from view.
The Helmsderfer panel commenced its analysis by noting that Helmsderfer did not argue that "partially hidden" had been given a definition that departs from the ordinary meaning of the term, but that the plain meaning of "partially hidden" also included fully hidden. The Court noted that the patent never utilized the term "partially hidden," other than in the base claim, but that the terms "generally" and "at least" appeared elsewhere, and pointed to Federal Circuit precedent indicating that different claim terms are presumed to have different meanings. The Court noted that nothing in this case rebutted this presumption and that if Helmsderfer had intended such a meaning for "partially hidden," it should have used such a term.
Next, the panel noted that a court may look to extrinsic evidence to determine the meaning of a claim term that does not contradict the intrinsic evidence. The Helmsderfer patent did not give any definition of "partially," thus it was not improper for the district court to look to dictionary definitions of "partially" while arriving at the plain meaning of a claim term.
Finally, the Federal Circuit panel addressed Helmsderfer's argument that the district court's claim construction excluded the preferred embodiment and all illustrated embodiments from the asserted claims. The Court noted a claim should not be construed to exclude disclosed embodiments when the term has multiple ordinary meanings consistent with the intrinsic record. However, the Court added that, although the construction given to "partially hidden from view" in the asserted claims does not include the disclosed embodiments, this does not mean that the disclosed embodiments are excluded from the scope of other claims in the patent. The Court noted that none of the other independent claims contained the term "partially hidden from view," thus it is possible that non-asserted claims encompass the disclosed embodiments. "It is often the case that different claims are directed to and cover different disclosed embodiments. The patentee chooses the language and accordingly the scope of his claims."
Practice Note: The decisions in PSN and Helmsderfer suggest that the existence of unasserted claims or claims that were canceled during prosecution may preclude application of the claim construction rule of avoiding a claim interpretation that excludes the preferred embodiment from the scope of the invention.
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