In CBT Flint Partners, LLC v. Return Path, Inc., 99 USPQ2d 1610 (Fed. Cir. 2011), CBT Flint Partners, LLC (“CBT”) appealed the District Court for the Northern District of Georgia’s grant of summary judgment of invalidity of claim 13 of U.S. Patent 6,587,550 (“the ‘550 patent”). CBT owns the ‘550 patent, as well as another patent, the ‘114 patent, which both relate to methods and systems for charging a fee for sending spam email to recipients. In the preferred embodiment of the ‘550 patent, the invention is implemented as part of an Internet Service Provider (“ISP”). When a sender attempts to send spam emails over the ISP network, the patented system determines whether this sender is an “authorized sending party,” i.e., a party who has agreed to pay a fee to the ISP. If the sender is an authorized sending party, the ISP will forward its spam emails to the intended recipients. If the sender is not an authorized sending party, the patented system will send a message to the sender, giving the sender the option to pay the fee and become an authorized sending party. If the sender does not pay this fee, its spam emails will not be forwarded over the network.
In August 2007, CBT sued Return Path, Inc. and Cisco Ironport Systems, LLC (“the Defendants”), alleging infringement of both the ‘550 and ‘114 patents by the Defendants’ “Bonded Sender” system. This system analyzes incoming emails to determine whether they came from an authorized computer and, if so, forwards them to their intended recipients. CBT asserted infringement of claim 13 of the ‘550 patent, as well as infringement of ten claims of the ‘114 patent.
On July 10, 2008, the district court issued a claim construction order, and the next day it granted summary judgment of invalidity of claim 13 of the ‘550 patent. All parties and the court agreed that claim 13 contained a drafting error where it recited “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.” The court determined that there were three reasonably possible corrections of this error: (1) delete the word “detect,” (2) delete the word “analyze,” and (3) add the word “and” between the words “detect” and “analyze.”
After considering the claim language and specification, the court held that the appropriate correction was subject to reasonable debate. It also noted that one of the inventors, who prosecuted the ‘550 patent application, testified that he could have meant to draft the claim in any of the three ways listed. As a result, the court held that under Novo Industries L.P. v. Micro Molds Corp., 350 F.3d 1348, 1354 (Fed. Cir. 2003), it was unauthorized to correct the error, rendering claim 13 invalid for indefiniteness. The parties then stipulated to noninfringement of all asserted claims of the ‘114 patent and the court entered final judgment in favor of the Defendants.
On appeal, the Federal Circuit held that the district court did have authority to correct the drafting error in claim 13 of the ‘550 patent and therefore reversed the district court’s summary judgment of invalidity for indefiniteness. The Federal Circuit held that there was an obvious and correctable error in the claim, the construction of which was not subject to reasonable debate, and remanded to the district court for further proceedings.
The Federal Circuit began by citing to I.T.S. Rubber Co. v. Essex Rubber Co., 272 U.S. 429, 442 (1926) for the proposition that it is well-settled that in a patent infringement suit, a district court may correct an obvious error in a patent claim. The Federal Circuit also noted that it qualified this statement in Novo Industries by holding 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.” The Federal Circuit then observed that in Ultimax Cement Manufacturing Corp. v. CTS Cement Manufacturing Corp., 587 F.3d 1339, 1353 (Fed. Cir. 2009), it further held that a district court must consider any proposed correction “from the point of view of one skilled in the art” when determining whether the district court had authority to correct a claim.
CBT argued that the question that determines indefiniteness is whether the claim would have the same meaning under all reasonable formulations and the Federal Circuit agreed. The Federal Circuit found that in this case, the district court erred by failing to consider the three possible corrections from the point of view of one skilled in the art. Here, the Federal Circuit determined that a person of skill in the art would find the claim to have the same scope and meaning under each of the three possible corrections.
First, if the word “detect” was deleted, the claim would require the computer to be programmed to analyze the email. But to be able to analyze the email, the computer would necessarily have to first detect the email.
Second, if the word “analyze” was deleted, the claim would require 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. To make this determination, however, would necessarily involve analysis of the email.
Finally, the addition of the word “and” between the words “detect” and “analyze” results in the same claim scope as the other two possible interpretations. Because both other interpretations involve both detection and analysis, the omission of the word “and” was an obvious error. A person of skill in the art would readily know that the meaning of the claim required insertion of the word “and” between the words “detect” and “analyze.” As such, the district court was not required to guess which meaning was intended in order to make sense out of the patent claim. See I.T.S. Rubber Co. v. Essex Rubber Co., 272 U.S. 429, 442 (1926) (“This is not in any real sense, a re-making of the claim; but is merely giving to it the meaning which was intended by the applicant and understood by the examiner.”). The error was obvious and the correction was not subject to reasonable debate, so the district court was authorized to make the correction.
The Federal Circuit further held that the district court erred in its heavy reliance on the inventor’s testimony that he was unsure what he meant by the language “detect analyze.” The Federal Circuit found that this testimony merely related to his recollection of how he intended to draft the claim and not to the meaning of the claim itself. The Federal Circuit also found that the district court incorrectly ignored the inventor’s testimony that the meaning of claim 13 would be the same under any of the three proposed interpretations. Therefore, this testimony supported CBT’s arguments.
Significance for Patentees and Defendants
CBT indicates that courts may occasionally assist patentees during litigation by correcting obvious drafting errors. Nevertheless, the takeaway from this case should not be that patentees can always rely on courts to correct errors in patent claims. CBT was fortunate here that all the reasonably possible corrections had the same scope and meaning. Often, however, this will not be true. Many situations of this kind will involve non-obvious errors or instances where the correction is subject to reasonable debate, even from the standpoint of one skilled in the art. Therefore, as always, patentees should diligently review claims during prosecution to prevent drafting errors, and should thoroughly review issued patents before suing on them.
And importantly, instead of relying on the district court to exercise discretion to correct the claim, it is important that patent owners recognize that they can correct such errors using Certificates of Correction under 35 U.S.C. § § 254 & 255. These provisions are relatively inexpensive and quick, and would have likely avoided the problems and delays associated with what occurred in CBT. Therefore, if possible, prior to initiating suit, patent owners should consider correcting errors rough this simple process.
Meanwhile, although this type of claim correction by a district court may be relatively rare, defendants should be aware that it can and will occur. Therefore, defendants should not rest their entire case on a finding of indefiniteness where there is an obvious claim drafting error, especially since not only can the United States Patent and Trademark Office correct such errors, so can district courts.