Print PDF

A Claim Error Obvious and Correctable from the Perspective of a Person of Ordinary Skill in the Art Held Not Invalid

10-1202
August 10, 2011

Decision icon Decision

Last Month at the Federal Circuit - September 2011

Judges: Lourie (author), Bryson, Linn

[Appealed from: N.D. Ga., Judge Thrash, Jr.]

In CBT Flint Partners, LLC v. Return Path, Inc., Nos. 10-1202, -1203 (Fed. Cir. Aug. 10, 2011), the Federal Circuit reversed the district court’s SJ of invalidity of claim 13 of U.S. Patent No. 6,587,550 (“the ’550 patent”) because the district court had authority to correct the supposed error found in the claim, vacated the district court’s rulings on costs, and denied CBT Flint Partners, LLC’s (“CBT”) cross-appeal for attorneys’ fees.

CBT owns the ’550 patent and U.S. Patent No. 6,192,114 (“the ’114 patent”), which both relate to methods and systems for charging a fee for sending unsolicited and unwanted e-mail (known as “spam”). In a preferred embodiment of the ’550 patent system, when a party sends a spam message to an intended receiving party, the Internet Service Provider determines whether the sender of the e-mail is an authorized sending party, and, if authorized, forwards the spam e-mail to the receiving party. If, however, the sending party is not authorized, the system sends a message to the sending party with an option to pay a fee and have the spam message forwarded to the recipient. Claim 13 of the ’550 patent, the only claim-at-issue in the appeal, recites, inter alia, “[a]n apparatus for determining whether a sending party . . . is an authorized sending party, the apparatus comprising: a computer in communication with a network, the computer being programmed to detect analyze the electronic mail communication sent by the sending party to determine whether or not the sending party is an authorized sending party or an unauthorized sending party . . . .” Slip op. at 3-4 (citation omitted).

CBT sued Cisco Ironport Systems, LLC (“Cisco”) and Return Path, Inc. (“Return Path”) for infringement of the ’550 and ’114 patents. The accused system analyzes each incoming e-mail message to determine whether the e-mail came from an authorized computer, and, if so, forwards it. The accused system, however, does not have any mechanism to permit the forwarding of e-mail from unauthorized computers to a recipient, even if the unauthorized sending party is willing to pay a fee.

The district court agreed with the parties that claim 13 contained a “drafting error”; specifically, the claim recites “the computer being programmed to detect analyze the electronic mail communication.” Id. at 4 (citation omitted). The district court determined that there were at least three reasonable corrections to rectify the drafting error: (1) delete the word “detect,” (2) delete the word “analyze,” or (3) add the word “and” between the words “detect” and “analyze.” The district court held that since the appropriate correction was subject to reasonable debate, it was therefore not authorized to correct the so-called drafting error, and, thus, the claim was invalid for indefiniteness. Cisco moved for a finding of an exceptional case and an award of attorneys’ fees, and submitted its bill of costs. The district court awarded costs but denied Cisco’s motion for declaration of an exceptional case and its request for attorneys’ fees. CBT appealed the district court’s SJ of invalidity of claim 13 of the ’550 patent and the court’s award of costs to Cisco. Cisco cross-appealed the district court’s denial of its motion for designation as an exceptional case and attorneys’ fees.

On appeal, the Federal Circuit agreed with CBT that claim 13 was not indefinite because there was “an obvious and correctable error in the claim, the construction of which is not subject to reasonable debate.” Id. at 8. First, the Court noted that in Novo Industries L.P. v. Micro Molds Corp., 350 F.3d 1348 (Fed. Cir. 2003), it held that a “district court can correct a patent only if (1) the correction is not subject to reasonable debate based on consideration of the claim language and the specification and (2) the prosecution history does not suggest a different interpretation of the claims.” Slip op. at 9 (quoting Novo Indus., 350 F.3d at 1357).

Second, the Federal Circuit concluded that the district court erred by holding that it was not authorized to “correct” the supposed “detect analyze” error. In particular, the district court failed to consider the three alternative corrections from the point of view of one skilled in the art. From that perspective, a person of skill in the art would find the claim to have “the same scope and meaning under each of the three possible meanings that the court found reasonable,” id. at 10, because each requires that the computer be programmed to “detect and analyze” the subject e-mail.

With respect to the district court’s first possible interpretation, the Federal Circuit noted that if the word “detect” were deleted, the claim would require that the computer be programmed to analyze the e-mail, but “the system would necessarily have to first detect the e-mail.” Id. Deleting the word “analyze,” in accordance with the district court’s second possible interpretation, would require that the computer be programmed to detect the e-mail and then “determine whether or not the sending party is an authorized sending party or an unauthorized sending party.” Id. at 11. The Court concluded, however, that the “determining step must include some form of analysis of the e-mail,” because “detecting an e-mail does not determine whether the user is an authorized sending party.” Id.

The Federal Circuit thus found that the district court’s final possible interpretation, inserting the word “and” between the words “detect” and “analyze,” would be readily known by a person of skill in the art “[b]ecause each of the three proposed reasonable interpretations would result in the same claim scope.” Id. Further, the specification supports this reading of the claim because it discloses a decoding step that the Court found “necessarily detect[ed] the e-mail message,” and a “compar[ing]” step, which, according to the Court, was “one of analysis.” Id. at 12. Thus, the district court was not required to guess which meaning was intended in order to make sense out of the patent claim.

In so finding, the Federal Circuit rejected Cisco’s assertion that correction of a claim must precede claim construction. Rather, the Court held that “[a]ny correction of a claim has to be consistent with the invention ‘described in the specification and drawings of the original patent,’” id. at 10 (citation omitted), and “[a] court therefore must consider how a potential correction would impact the scope of a claim and if the inventor is entitled to the resulting claim scope based on the written description of the patent,” id.

Finally, the Federal Circuit found that the district court erred by relying too heavily on one portion of the inventor’s testimony, which the district court misinterpreted, and by ignoring the inventor’s testimony that the meaning of the claim would be the same under each of the three interpretations because both detection and analysis were necessary to determine whether the sending party was authorized.

Accordingly, the Federal Circuit reversed the district court’s SJ of invalidity of claim 13 of the ’550 patent, vacated the district court’s rulings on costs because Cisco was no longer a prevailing party, denied the cross-appeal, and remanded to the district court for further proceedings consistent with the Court’s opinion.

Summary authored by Ruby Jain Natnithithadha, Esq.