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CAFC: Unasserted/Cancelled Claims are "Probative Evidence" of Embodiments Covered

By Two-Seventy-One Patent Blog

PSN Illinois, LLC v. Ivoclar Vivadent, Inc. (2007-1512)

After reexamination, PSN was left with a single claim in a patent covering a method of fabricating porcelain veneers for teeth. The method recited the step of eroding away a "statute" of a tooth from a porcelain veneer restoration "leaving said restoration ready for mounting on said tooth." The claim language did not define what was meant by "ready for mounting," and the specification provided no explicit definition.

While the summary of the invention provided additional examples of a restoration that was "ready for mounting," the district court focused on a preferred embodiment in the detailed description, which was stated to be "a feature of this invention." Taking this narrow construction, the district court granted summary judgment of noninfringement.

On appeal, the CAFC found the district court incorrectly placed greater weight on the detailed description, noting that the detailed description expressly provided that the embodiment "may" be used when performing the claimed method. Also, PSN cited the recent CAFC case of Oatey Co. v. IPS Corp., 514 F.3d 1271, 1277 (Fed. Cir. 2008), which held that

At leas[t] where claims can reasonably [be] interpreted to include a specific embodiment, it is incorrect to construe the claims to exclude that embodiment, absent probative evidence on the contrary (emphasis added).

While finding discrepancies in the claim construction, the CAFC nevertheless found that "'ready for mounting' can and should be construed in a way that encompasses the preferred embodiment."

We note that Oatey is not a panacea, requiring all claims to cover all embodiments. Instead, courts must recognize that disclosed embodiments may be within the scope of other allowed but unasserted claims. Likewise, during prosecution, an applicant may have cancelled pending claims but not amended the specification to delete disclosure relevant only to the cancelled claims. In such cases, unasserted or cancelled claims may provide "probative evidence" that an embodiment is not within the scope of an asserted claim.

AFFIRMED

Full post as published by Two-Seventy-One Patent Blog on May 06, 2008 (boomark / email).