Lydall v. Federal Mogul (CAFC 2009-1135) non-precedential

Some case law pointers, leaving aside the tufts of the claims.

A single embodiment constricts claims to the breadth of the specification.

We have stated that "when the preferred embodiment is described in the specification as the invention itself, the claims are not necessarily entitled to a scope broader than that embodiment." Chimie v. PPG Indus., 402 F.3d 1371, 1379 (Fed. Cir. 2005); see Honeywell, 452 F.3d at 1318 (construing claim term to include fuel filter because "[o]n at least four occasions, the written description refers to the fuel filter as 'this invention' or 'the present invention'"); SciMed, 242 F.3d at 1343 (construing term to include feature characterized as "the present invention"). In other words, when a patentee consistently describes one embodiment as "the present invention," "[t]he public is entitled to take the patentee at his word." Honeywell, 452 F.3d at 1318; see also SciMed, 242 F.3d at 1341 ("Where the specification makes clear that the invention does not include a particular feature, that feature is deemed to be outside the reach of the claims of the patent, even though the language of the claims, read without reference to the specification, might be considered broad enough to encompass the feature in question."). Such is the case here.

The specification trumps the file history.

We also agree with the district court that Lydall's reliance on the prosecution history and the doctrine of claim differentiation is unpersuasive. "Representations during prosecution cannot enlarge the content of the specification." Biogen, Inc. v. Berlex Labs., Inc., 318 F.3d 1132, 1140 (Fed. Cir. 2003). Thus, when the prosecution history appears in conflict with the specification, any ambiguity must be resolved in favor of the specification. See id. The specification is the "best source for understanding a technical term," to be supplemented, "as needed, by the prosecution history." Phillips, 415 F.3d at 1315 (quoting Multiform Desiccants, Inc. v. Medzam, Ltd., 133 F.2d 1473, 1478 (Fed. Cir. 1998)).

Different words in different claims don't necessarily mean different scope.

The patentee's efforts during the prosecution of the reissue patent to enlarge the claims beyond what the specification discloses also must fail. Similarly, Lydall cannot rely on claim differentiation to expand the scope of the claim term. See Nystrom v. Trex Co., 424 F.3d 1136, 1143 (Fed. Cir. 2005) ("[S]imply noting the difference in the use of claim language does not end the matter. Different terms or phrases in separate claims may be construed to cover the same subject matter where the written description and prosecution history indicate that such a reading of the terms or phrases is proper.").

Affirmed.