Last Month at the Federal Circuit
Last Month at the Federal Circuit

May 2012

Defining Words Appearing in Construction of a Claim Term, Not the Claim Term Itself, Also Requires Following the Intrinsic Evidence


Judges:  Lourie (author), Dyk (dissenting-in-part), Prost
[Appealed from N.D.N.Y., Senior Judge Kahn]

In Advanced Fiber Technologies (AFT) Trust v. J&L Fiber Services, Inc., No. 11-1243 (Fed. Cir. Apr. 3, 2012), the Federal Circuit revised the district court’s construction of a term appearing only in the court’s construction of a claim term, and therefore vacated SJ of noninfringement.  The Court declined to address the district court’s denial of SJ of no invalidity but affirmed SJ of no willful infringement.

The technology at issue relates to devices used to filter contaminants from paper pulp mixtures known as “stock” by passing the stock through screens with holes.  The asserted U.S. Patent No. RE39,940 (“the ’940 patent”) resulted from a reissue of U.S. Patent No. 5,200,072 (“the ’072 patent”).  During prosecution of the reissue application, Advanced Fiber Technologies (AFT) Trust (“AFT”) argued against a rejection in light of a prior art patent to Gillespie.  Specifically, AFT argued that the ’072 patent used terms of pulp treatment art and offered definitions from the Handbook of Pulp and Paper Terminology (the “Handbook”).  According to the Handbook, “screen” and “screen plate” meant a perforated barrier.  AFT further argued that Gillespie taught slots “over three times the size” compared with the size of the slots in the claimed invention.  Slip op. at 7.  In response, the PTO withdrew the rejection and reissued the patent as the ’940 patent.

AFT sued J&L Fiber Services, Inc. (“J&L”), which asserted noninfringement and invalidity based on a number of prior art references.  The district court construed “screening medium” and “screening plate” as “a perforated barrier through which stock is passed to remove oversized, troublesome, and unwanted particles from good fiber.”  Id. at 8 (quoting Advanced Fiber Techs. Tr. v. J&L Fiber Servs., Inc.,
751 F. Supp. 2d 348 361 (N.D.N.Y. 2010)).  At AFT’s request, the district court further construed “perforated,” which appeared in the district court’s construction but not the claims themselves.  The district court looked to general and technical dictionary definitions to conclude that “perforated” means “pierced or punctured with holes.”  Id. (citation omitted).  The district court observed that the patent specification contains a “one-sentence mention that ‘a wedgewire screening plate may be used,’” but viewed the disclosure as insufficient to overcome the ordinary meaning of “perforated.”  Id. (citation omitted).  Finally, the district court viewed AFT’s statement regarding the sizes of holes in the prior art and the claimed invention as a disavowal of claim scope and therefore limited the claims to openings and slots no greater than 0.254 mm.

Based on its claim constructions, the district court granted SJ of noninfringement because J&L’s accused product used wedgewire construction and therefore did not meet the court’s construction for “perforated.” It further denied SJ of no invalidity and dismissed AFT’s claim of willful infringement.  Regarding willfulness, the district court reasoned that J&L presented “credible” and “compelling” arguments regarding noninfringement and invalidity.  Id. at 10.


“The fact that an embodiment is disclosed in a single sentence is not a license to ignore that disclosure.”  Slip op. at 16-17.

On appeal, the Court reversed the district court’s construction of perforated, holding that AFT had not restricted the term to structures pierced or punctured with holes.  It agreed that sometimes the courts may have to further define words that appear only in the construction of a claim term, not the claim term itself.  As the Court explained, such metaconstruction should follow the guiding principles of claim construction—specifically, focusing on intrinsic evidence.  It held that the district court erred by elevating dictionary definitions above the specification and claims.  Specifically, the Court looked to the claims generically reciting “screening medium” as “having a plurality of openings therethrough” and the specification including an embodiment of a perforated barrier made by assembling wires.  Id. at 16.  That the embodiment only appeared in a brief passage did not bother the Court, which explained that
“[t]he fact that an embodiment is disclosed in a single sentence is not a license to ignore that disclosure.”  Id. at 16-17.  Regarding the prosecution history, the Court held that AFT had limited the claims to “perforated” plates but had not defined “perforated” to require piercing or puncturing.  Accordingly, the Court reversed SJ of noninfringement.

Turning next to the district court’s construction of “slots” and “openings” as less than 0.254 mm, the Court agreed that AFT had disclaimed any larger opening when it argued that the prior art taught holes “over three times the size of the slot width of the present invention.”  Id. at 19.

Regarding invalidity, the Court explained that denial of SJ does not create an appealable issue. Specifically, because the denial of SJ of no invalidity was not “inextricably intertwined” with the grant of SJ of noninfringement and because review of the invalidity issue was not “necessary to ensure meaningful review” of the noninfringement issue, the Court declined to review the invalidity determination. Id. at 19-20.

Finally, the Court affirmed SJ of no willful infringement, reasoning that J&L had asserted objectively reasonable defenses to the suit.  The fact that the Court had vacated SJ of noninfringement did not affect its analysis.

Judge Dyk dissented-in-part, explaining that in his view, the prosecution history showed that “perforated” required holes or openings made through an otherwise solid object.  Because the patentee had distinguished prior art using a “wedgewire construction” as not within the scope of claims to a “screening medium” or “screening plate,” Judge Dyk would have affirmed the district court’s claim construction and SJ of noninfringement.  As to the specification’s disclosure of a wedgewire embodiment, Judge Dyk explained that a patent need not claim all embodiments, particularly when the applicant changes the claim scope during prosecution.