On Wed., Feb. 1, 2012, in Thorner v. Sony Computer, No. 2011-1114, the Federal Circuit (Rader, Moore and Aiken) reversed a claim construction because the district court improperly used the specification to limit claim terms.

The Court provides a good summary review of the two exceptions to the general rule that claim terms are construed under their ordinary meaning: where the patentee (1) acts as its own lexicographer or (2) expressly disavows claim scope.  The defendant argued that “attached to said pad” must be limited to an attachment to the outside of a pad, because the specification consistently used “attached” to refer to such embodiments and used the term “embedded” to refer to other embodiments having an attachment within the pad.  The Court ruled that neither the lexicographer nor disavowal exceptions applied in this case, and construed the term “attached” under its ordinary meaning with the term “embedded” being a subset of “attached”.

The Court also provides some insight into construing terms that present issues of degree, ruling that such issues present factual questions of infringement.  The Court addressed the ambiguous term “flexible pad” – e.g., although steel may flex, is it “flexible” within the scope of the claim.  The district court sought to limit the degree of flexibility by construing “flexible” to mean “capable of being noticeably flexed with ease” (which seems to present more questions of degree – what is “noticeably” and “ease”).  The Federal Circuit reversed, stating that “[t]he task of determining the degree of flexibility, the degree of rigidity that amounts to ‘semi-rigid,’ is part of the infringement analysis, not part of the claim construction.”